Colloquia Archive

Pete Schloerb (UMass Amherst)

April 21, 2016, 4 p.m. — LGRT 1033
Title: Living with a Comet

Abstract: In August 2014 the European Space Agency's Rosetta spacecraft made a successful rendezvous with comet 67P/Churyumov-Gerasimenko approximately one year before the perihelion of the comet's orbit. Rosetta continues to fly with 67P, studying the nature of the nucleus as well as the composition and properties of the gas and dust produced by the comet's activity. The ability to observe the comet's behavior from close up and over the long time period as it approached and receded from the Sun has provided many insights into the comet's nature and behavior. In this presentation I will review some key points about comets in general and provide an overview of the Rosetta Mission and some of its major results. I will then describe some of my own work studying the thermal properties of the comet nucleus with the millimeter-wave MIRO instrument on the Rosetta Orbiter.

George Rieke (University of Arizona)

April 19, 2016, 4 p.m. — LGRT 1033
Title: JWST is Coming to a Lagrangian Point Near You!

Abstract: The James Webb Space Telescope has just passed two huge milestones; completion of: 1.) the telescope itself; and 2.) its entire instrument package. The project has held schedule (and budget) since being replanned in 2011 and is heading toward launch in October, 2018. Although there are many more steps to take before then, most notably a full system test in the first part of 2017, thinking about how to use our new flagship space telescope can no longer be safely postponed. We are within a year of fully defining the first guaranteed time observational programs, an Early Release Science program will allocate 500 hours roughly in July, 2017, and the call for General Observer proposals will be released in November 2017. This talk will focus on the capabilities of the observatory, emphasizing the advances over present (and even some future) facilities, with examples of the science it will enable. JWST will redefine our views of topics ranging from exoplanets to the first galaxies and super-massive black holes.

Rongmon Bordoloi (MIT)

April 14, 2016, 4 p.m. — LGRT 1033
Title: Mapping the Circumgalactic Medium: The Origin and Structure of t

Abstract: Our current understanding of how galaxies evolve over cosmic time is highly incomplete without understanding what is now known as a major baryonic component: the Circumgalactic medium (CGM). The CGM contains both the fuel for and the end products of star-formation in galaxies, but these regions are relatively hard to explore owing to their extremely low gas densities. The installation of the Cosmic Origins Spectrograph (COS) aboard the Hubble Space Telescope (HST) has allowed us to make major advances in our ability to systematically map and study these diffuse regions of gaseous galaxy halos. I will present the latest results form two large HST/COS surveys which systematically characterize the CGM in HI and metal lines over more than three decades of galactic stellar mass. The CGM as seen by these programs is nearly ubiquitous in HI, patchy in most metals, and generally cool and bound. I will describe the implications of these results for galactic fueling and quenching, and speculate on where we might go from here.

Rachel Bezanson (University of Arizona)

April 7, 2016, 4 p.m. — LGRT 1033
Title: The Surprisingly Complex Lives of Massive Galaxies

Abstract: Massive galaxies reside in the densest and most evolved regions of the Universe, yet we are only beginning to understand their formation history. Once thought to be relics of a much earlier epoch, the most massive local galaxies are red and dead ellipticals, with little ongoing star formation or organized rotation. In the last decade, observations of their assumed progenitors have demonstrated that the evolutionary histories of massive galaxies have been far from static. Instead, billions of years ago, massive galaxies were morphologically different: compact, possibly with more disk-like structures, and on-going star formation. The details of this observed evolution can place constraints on the physical processes that have driven massive galaxy evolution through cosmic time. I will discuss on-going observational studies of the structure, dynamics, and compositions of massive high-redshift galaxies. Finally, I will outline prospects for further understanding of the history of these intriguing objects with next generation observatories and instruments.

Chuck Hailey (Columbia University)

March 31, 2016, 4 p.m. — LGRT 1033
Title: A View of the Center of the Milky Way Galaxy in High Energy X-ra

Abstract: I discuss recent observations of the Galactic Center with the Nuclear Spectroscopic Telescope Array (NuSTAR). NuSTAR launched in 2012 and carries the first true focusing telescopes capable of making images of the sky in high energy (hard) X-rays – those above 10 keV. NuSTAR’s twin telescopes, operating in the 3-79 keV energy band, provide an order of magnitude better angular resolution and two to three orders of magnitude better sensitivity than previous hard X-ray missions. I provide a brief introduction to the NuSTAR observatory and its capabilities, and explain why the X-ray optics permit such substantial advances in performance over previous missions. One of the major goals of the NuSTAR mission was to conduct a detailed hard X-ray survey of the objects around the Galactic Center such as the supermassive black hole, pulsar wind nebulae, non-thermal filaments and molecular clouds. NuSTAR also conducted a deep survey to try and identify the origin of the thousands of unidentified point sources discovered previously by the Chandra Observatory. I will describe some of the highlights of this survey. NuSTAR also detected some surprises, including a hitherto undetected diffuse, hard X-ray emission whose origin was unclear. I will discuss recent attempts to unravel this mystery.

Jorge Moreno (Cal Poly Pomona)

March 24, 2016, 4 p.m. — LGRT 1033
Title: Galaxy Mergers on FIRE: Mapping Star Formation

Abstract: Galaxy mergers and interactions are responsible for generating bursts of star formation, for changing galactic morphology in dramatic ways, and for triggering single and dual active galactic nuclei. In this talk, I will unveil the very first results from a novel suite of high-resolution galaxy merger simulations, based on the “Feedback In Realistic Environments” (FIRE) model. This model treats energy and momentum-driven feedback from young stars and SN explosions explicitly, which acts directly on resolved star-forming clouds within the ISM. Moreover, this framework relies on a new meshless Lagrangian hydro code, GIZMO, which solves many problems associated with older solvers. Our first work focuses on the spatial localization of star formation. In particular, we confirm results from previous work: galaxy-galaxy interactions enhance nuclear star formation, and suppress it at large galacto-centric radii (Moreno et al. 2015). However, two major differences are found. First, star-formation enhancement and suppression are not as dramatic as in older models. Secondly, the interaction-induced nuclear starburst has a larger spatial extent. These differences are a reflection of the fact that, in our new models, non-axisymmetric gravitational torques are not as effective at driving fuel into the central regions as in older sub-grid based models. This suite of merger simulations is ideal for making predictions for, and interpreting results from, observations by new-generation integral field spectroscopic surveys, such as CALIFA, MaNGA and HECTOR.

Charlie Conroy (CfA)

March 10, 2016, 4 p.m. — LGRT 1033
Title: Semi-Resolved Stellar Populations in Space & Time

Abstract: Historically, the analysis of stellar populations has been pursued in two limiting cases: spatially-resolved stellar populations in the color-magnitude diagram, and integrated light observations of distant systems. In between these two extremes lies a rich and relatively unexplored realm of observational signatures. In this talk I will describe our recent efforts to develop techniques and analyze datasets exploiting the “semi-resolved” stellar population regime, both spectroscopically and temporally. These new tools will likely play an important role in maximizing the science returns from next generation ground and space-based facilities.

Marc Kuchner (NASA)

March 3, 2016, 4 p.m. — LGRT 1033
Title: DiskDetective.org: Finding Homes for Exoplanets through Citizen

Abstract: The Disk Detective project is scouring the data archive from the WISE all-sky survey to find new debris disks and protoplanetary disks--the dusty dens where exoplanets form and dwell. Volunteers on this new citizen science website have already performed more than 1,6 million classifications, searching a catalog 8x the size of any published WISE survey. We follow up candidates using ground based telescopes in California, Arizona, Chile, Hawaii and Argentina. We ultimately expect to increase the pool of known exozodiacal disks by ~400 and triple the solid angle in clusters of young stars examined with WISE, providing a unique new catalog of isolated disk stars, key planet-search targets, and candidate advanced extraterrestrial civilizations.

Marc Kuchner (NASA)

March 2, 2016, 3:30 p.m. — ILC S211
Title: Marketing for Scientists

Abstract: The Marketing for Scientists workshop introduces scientists to fundamental techniques from the business world like sales, branding and relationship building. This 90 minute interactive program uses the examples of Steve Jobs and George Lucas to show that marketing can be a positive, even healing force. Learn how to get your ideas across more vividly, win more support for your work, and shape the public debate while maintaining your integrity and building your reputation in the scientific community. For more information, go to http://marketingforscientists.com/workshop

LMT Jamboree (FCAD members with LMT)

Feb. 25, 2016, 4 p.m. — LGRT 1033
Title: Various

Abstract: Brief 5 minute presentation from all FCAD members with LMT programs.

Shep Doeleman (MIT)

Feb. 18, 2016, 4 p.m. — LGRT 1033
Title: The Event Horizon Telescope:Imaging & Time-Resolving a Black Hol

Abstract: A convergence of high bandwidth radio instrumentation and Global mm and submm wavelength facilities are enabling assembly of the Event Horizon Telescope (EHT): a short-wavelength Very Long Baseline Interferometry (VLBI) array, which can observe the nearest supermassive black holes with Schwarzschild Radius resolution. Initial observations with the EHT have revealed event horizon scale structure in SgrA*, the 4 million solar mass black hole at the Galactic Center, and in the much more luminous and massive black hole at the center of the giant elliptical galaxy M87. Over the next 2-3 years, this international project will add new sites and increase observing bandwidth to focus on astrophysics at the black hole boundary. EHT data products will have an unprecedented combination of sensitivity and resolution with excellent prospects for imaging strong GR signatures, detecting magnetic field structures through full polarization observations, time-resolving black hole orbits, testing GR, and modeling black hole accretion, outflow and jet production. This talk will describe the project and the latest EHT observations.

Hilke Schlichting (MIT)

Feb. 11, 2016, 4 p.m. — LGRT 1033
Title: Crash, Boom, Bang: Giant Impacts & the Formation of Planets at h

Abstract: Recent observations by the Kepler space telescope have led to the discovery of more than 4000 exoplanet candidates consisting of many systems with Earth- to Neptune-sized objects that reside well inside the orbit of Mercury, around their respective host stars. How and where these close-in planets formed is one of the major unanswered questions in planet formation. I will present recent results concerning initial disk masses and atmospheric mass-loss due to impacts and will discuss their implications for terrestrial planet formation in our Solar System and the origin of close-in Super-Earths and Mini-Neptunes.

Adam Kraus (UT Austin)

Feb. 4, 2016, 4 p.m. — LGRT 1033
Title: The Ruinous Impact of Close Binaries on Planetary Systems

Abstract: The majority of searches for extrasolar planets have concentrated exclusively on single stars, avoiding close binary systems where the companion might complicate the observations and analysis. However, the majority of solar-type stars have binary companions, and they should exert a strong dynamical influence on any planetary system. I will discuss new discoveries that outline the influence of stellar multiplicity at different stages of planet formation and evolution, enabled by a high-resolution imaging technique (nonredundant aperture-mask interferometry) that opens the discovery space for binary companions on solar-system scales (5-50 AU) even around relatively distant stars (100-500 pc). First, I will summarize the results of a combined multiplicity and disk census of 1-10 Myr old stars in several star-forming regions. These results demonstrate the ruinous effect of close binary companions upon protoplanetary disks; at ages when disks are still ubiquitous among single stars and wide binaries, the corresponding disk fraction among close binaries is suppressed by a factor of 3-4. I will then describe an ongoing program to study the multiplicity of Kepler planet host stars, for which my results indicate that the planet occurrence rate is similarly suppressed among close binaries. Finally, I will discuss how these results change the interpretation of planet formation and disk dissipation around single stars, given that almost all of them appear to host disks for at least 2-3 Myr, and what this might mean for the timescales and mass budgets for assembling planetary systems.

Warren Skidmore (TMT)

Jan. 28, 2016, 4 p.m. — LGRT 1033
Title: The Thirty Meter Telescope Observatory: The Next Generation Grou

Abstract: After a short construction status update, I will describe how the telescope design was developed to support a broad range of observing capabilities and how the observatory is being engineered. I'll discuss some of the observational capabilities that the Thirty Meter Telescope will provide and some of the areas of study that will benefit from the TMT's capabilities, specifically synergistic areas with new and future proposed astronomical facilities. Finally I will describe the avenues through which astronomers can have some input in the planning of the project and potential NSF partnership, prioritizing the development of 2nd generation instruments and directing the scientific aims for the observatory.

Qiang Yuan (UMass Amherst)

Jan. 21, 2016, 4 p.m. — LGRT 1033
Title: Flares from low-luminosity SMBHs

Abstract: Low-luminosity supermassive black holes (LL-SMBHs) represent the majority (~90%) of SMBHs in our Universe. The accretion of matter onto LL-SMBHs and its feedback on the galaxies is one of the most fundamental problems in astronomy. The study of LL-SMBHs is, however, difficult due to their low level of emission. As an extreme representative of LL-SMBHs, Sgr A in our own Galaxy provides us with a unique opportunity to study the accretion process in great detail, primarily due to its proximity. The study of Sgr A can even allow us to probe the physics near the event horizon of the black hole. The population of LL-SMBHs, on the other hand, can be probed via the tidal disruption of (sub-)stellar objects. The study of tidal disruption events enables us to understand such fundamental questions as the jet formation and associated particle acceleration, as well as the density and magnetic field structures in the galactic nuclei. This talk will review the recent developments on these subjects and introduce some of our works, including the X-ray view of Sgr A*, with an emphasis on its variabilities, and the multi-wavelength view of tidal disruption events, with an emphasis on the millimeter observations. We propose that it is just the right time for millimeter monitoring of these phenomena, which will play a very important role in advancing the understanding of LL-SMBHs.

Juna Kollmeier (Carnegie Observatory)

Dec. 10, 2015, 3:45 p.m. — 1033 LGRT
Title: Cosmological Calorimetry:The nature of the intergalactic mediu

Abstract: The Lyman alpha forest remains one of the most robust predictions of cosmological hydrodynamic simulations. Lyman alpha absorption lines have been used for decades to trace cosmic structures that -- only recently, with the exquisite sensitivity achievable with modern instruments -- are beginning to be detected in emission as well. I will discuss the predicted morphology of the Lyman alpha forest and the possibility of revealing this structure with Lyman alpha imaging surveys. The emission signal is dependent on the ionizing background radiation which, at high redshift, is well-understood and constrained. However, I will show that at low redshift there is a huge mismatch between our expectations and observations. I describe a factor of 5 discrepancy between the value of the photoionization rate required to match cosmological models of the z = 0.1 intergalactic medium to observations of the Lyman alpha forest and the value predicted by state-of-the-art models that account for the emissivity of stars and quasars over time. Examining potential resolutions to this problem, I will demonstrate that solving it requires, at minimum, a substantial revision of our thinking about the low redshift universe.

Jo Bovy (University of Toronto)

Dec. 3, 2015, 3:45 p.m. — 1033 LGRT
Title: What drives the evolution of the Milky Way's disk?

Abstract: Observations of the structure and dynamics of different stellar populations in the Milky Way's disk provide a unique perspective on Galactic growth, evolution, and dynamics over cosmic time. I will review our current knowledge of the chemo-orbital structure of the disk and the major outstanding questions. I will then discuss new measurements of the kinematics and chemistry of stars over a large part of the Galactic disk from the APOGEE survey and the new insights these measurements provide about the formation and evolution of the Milky Way's disk.

Nicolas Bouche (IRAP)

Nov. 19, 2015, 3:45 p.m. — 1033 LGRT
Title: The 3D view of galaxy formation and gas flows

Abstract: In the past 5 years, astronomers have found that star-forming galaxies do form a 'main-sequence', from the almost linear relationship between SFR and M* requiring a constant gas supply and that star-forming galaxies are mostly disks, even at redshifts z=2, with large angular momentum. In contrast, the role of galactic wind has yet to be determined on the evolution of galaxies. On the one hand, strong winds are expected to enrich the inter-galactic medium, but on the other hand, supernovae feedback cannot be too strong as it would destroy the formation of disks. I will describe the most recent observations on gas in- and out-flows using 3D imaging spectroscopy performed with the VLTs and Keck, and future prospects with mm and submm facilities using a new 3D algorithm.

Daniela Calzetti (University of Massachusetts Amherst)

Nov. 12, 2015, 3:45 p.m. — 1033 LGRT
Title: Star Formation Across Space

Abstract: Fundamental questions remain unanswered in understanding galactic-scale star formation, despite many decades of investigation and progress. These include: how do stars cluster in galaxies, and how do these structures evolve in time? Do we actually have a clustered' anddiffuse' mode of star formation? When structures remain bound (star clusters), how do their populations evolve? How are they related to the galactic-scale star formation? Is the stellar Initial Mass Function universal? How are popular star formation rate indicators affected by the recent star formation history of a galaxy? How are these effects impacting our understanding of the scaling laws of star formation with the gas reservoir? The answers to these questions inform our theories for the evolution of galaxies through cosmic times. Many of these questions are being addressed by recent projects that combine UV and high-angular resolution with the Hubble Space Telescope, and which I will describe together with the results they have obtained so far.

Cara Battersby (CfA)

Nov. 5, 2015, 3:45 p.m. — 1033 LGRT
Title: The Milky Way Laboratory for Star Formation

Abstract: Our home Galaxy, the Milky Way, is our closest laboratory for understanding physical processes throughout the Universe. Submillimeter observations of the cool, dense gas and dust in our Milky Way provide insights on universal processes including how stars form in both 'regular' and 'extreme' environments and how gas is organized on galactic scales. On a tour through our Milky Way Laboratory, I will discuss 1) how we can use long, skinny molecular clouds, potential "Bones of the Milky Way," to trace our Galaxy's spiral structure, 2) how large surveys of our Galaxy have revealed that star clusters continue to grow even as they are forming, and 3) how observing the Central Molecular Zone (the inner few hundred parsecs of our Galaxy) can help us learn more about the conversion of gas into stars during the peak of cosmic star formation (z~2).

Francesca Civano (Yale University)

Oct. 29, 2015, 3:45 p.m. — 1033 LGRT
Title: X-rays from the COSMOS Survey

Abstract: Observations indicate that supermassive black holes (SMBHs) ordinarily
dwell at the centers of local galaxies. Scaling relations have been
identified between SMBHs and many large scale properties of the host
galaxies that point to a joint cosmic evolution. Is this evolution
regulated by the galaxy or by the black hole? Is star-formation
triggering black hole activity or vice versa?

For more than 30 years, X-ray surveys have provided a unique and
powerful tool to find and study accreting SMBHs in the distant
Universe. In the past decade alone, dozens of surveys in the 0.5-10
keV band with XMM-Newton and Chandra have covered a wide range in area
and X-ray flux, corresponding to a similarly wide range of volume
covered in the Universe. The advent of the NuSTAR telescope, with its
3-80 keV energy response, allows us to now complement the "soft"
surveys, providing the ability to characterize the whole population,
including highly obscured sources.

In this talk, I will focus on the results I obtained using the COSMOS
field X-ray surveys. I will highlight the importance of X-ray studies
to compile a (quasi-) complete and unbiased sample of active SMBHs,
suitable to study the mutual relation between the supermassive black
hole and its host galaxy across the Universe.

I will briefly discuss about the future and the idea of achieving
fainter X-ray fluxes over large areas on legacy fields to match with
upcoming deep optical and near-infrared data (JWST, HyperSuprimeCam,
WFIRST).

Jeyhan Kartaltepe (RIT)

Oct. 22, 2015, 3:45 p.m. — 1033 LGRT
Title: AGN in Infrared Galaxies and the Evolving BPT Diagram

Abstract: We are undertaking an observational campaign to obtain near-infrared spectroscopy for distant galaxies in the COSMOS field using the FMOS instrument on Subaru. With this spectroscopy we can detect key rest-frame optical emission lines for galaxies out to z~1.7. In this talk, I will focus on the subset of 123 galaxies selected in the far-infrared with Herschel. These galaxies are highly obscured and known to have a high AGN fraction based on detections at other wavelengths. This is the largest sample of infrared galaxies with near-infrared spectroscopy at these redshifts. The far-infrared selection results in a sample of galaxies that are massive systems that span a range of metallicities in comparison with previous optically selected surveys, and thus has a higher AGN fraction and better samples the AGN branch. Using this sample, and other optically selected samples, we investigate how the BPT diagram evolves over time and how this evolution agrees with the prediction of the models of Kewley et al. 2013. We find that a large fraction of our IR-selected sample are BPT-selected AGN using their new, redshift dependent classification line and find large agreement with other methods of identifying AGN. Additionally, we identify new, likely obscured AGN that were not identified at other wavelengths and discuss the properties of these objects in detail.

Rosalba Perna (Stony Brook)

Oct. 15, 2015, 3:45 p.m. — 1033 LGRT
Title: Highly magnetic neutron stars: bewildering astrophysical laborat

Abstract: Anomalous X-ray Pulsars and Soft Gamma-Ray Repeaters (SGRs) are young neutron stars characterized by high X-ray quiescent luminosities, outbursts, and, in the case of SGRs, sporadic giant flares. They are believed to be magnetars, that is neutron stars powered by ultra-strong magnetic fields. However, the diversity of their behaviours, and, especially, the observation of magnetar-like bursts from 'low-field' neutron stars, has been a theoretical puzzle. In the first part of the talk, I will discuss results of long-term MHD simulations which, by following the evolution of magnetic stresses within the neutron star crust, have allowed to relate the observed magnetar phenomenology to the physical properties of the neutron stars, and in particular to their age and magnetic field strength and topology. The dichotomy of 'high-B' field pulsars versus magnetars is naturally explained, and occasional outbursts from old, low B-field neutron stars are predicted. In the second part of the talk, I will discuss how observations of highly magnetized neutron stars can be handy tools in the cosmological domain, and in particular as a way to set constraints on the hypothetical particle 'axion'.

Dan McIntosh (UMKC)

Oct. 8, 2015, 3:45 p.m. — 1033 LGRT
Title: Galactic Capitalism: the Buildup of a Bimodal Galaxy Population

Abstract: Our understanding of the universe is intimately tied to our study of galaxies. These behemoths are the birth places of all stars, which in turn are the crucibles creating the chemistry necessary for life. Physically, galaxies are dense concentrations of normal baryonic matter at the centers of deep gravitational wells of dark matter that define the underlying backbone of the cosmos. As such, the formation of new suns turns galaxies into blazing beacons that allow us to map the universe in both time and space. Yet, star formation has been steadily waning since "Cosmic High Noon", an epoch 10 billion years ago when galactic activity was booming. Conversely, individual galaxies continue to amass stars to the present day, and the number of spheroidal heavy weights is ballooning. In other words, a key feature of cosmic history is a 'galactic capitalism' of mergers and acquisitions that is producing a growing divide in the bimodal galaxy population of the haves' and thehave nots'. The growth of galaxies and the simultaneous decline of star formation are understood broadly in the context of the standard cosmological model. Yet, an enduring mystery remains as to what exactly is killing off the production of new stars and what is reshaping disks into spheroidal galaxies at all cosmic epochs. I will discuss the latest theories of galaxy formation and growth, and focus on recent advances my team has been involved with that shed new light on the physical processes that quench star formation and reshape the structure of galaxy giants.

Fred C. Adams (University of Michigan)

Oct. 1, 2015, 3:45 a.m. — 1033 LGRT
Title: Effects of Clusters on their Constituent Solar Systems and Possi

Abstract: Most stars -- and most solar systems -- form within groups and clusters. One objective of this work is to explore how these star forming environments affect the solar systems forming within them via three channels: dynamical interactions, elevated radiation fields, and increased particle fluxes. The discussion starts with the dynamical simulations, which are used to study how cluster evolution depends on system size and initial conditions. Multiple realizations of equivalent cases are used to build up a statistical description of these systems, e.g., distributions of closest approaches and radial locations. These results provide a framework from which to assess the effects of clusters on solar system formation. Distributions of radial positions are used in conjunction with UV luminosity distributions to estimate the radiation exposure of circumstellar disks. Photoevaporation models determine the efficacy of radiation in removing disk gas and compromising planet formation. The distributions of closest approaches are used in conjunction with scattering cross sections to determine probabilities for solar system disruption. Finally, we determine the distributions of radioactive nuclei that are provided to circumstellar disks, where they enhance ionization and heating. This work provides a quantitative determination of the effects of clusters on forming solar systems. In the second part of the talk, these results are used to place constraints on the possible birth environments for our own solar system.

Lorenzo Sironi (Harvard University)

Sept. 24, 2015, 3:45 p.m. — 1033 LGRT
Title: The Journey of High-Energy Photons in Blazar Jets

Abstract: We investigate the origin and the fate of high-energy photons in blazar jets, by means of analytical theory and first-principles particle-in-cell (PIC) kinetic simulations. In magnetically-dominated jets, magnetic reconnection is often invoked as a mechanism to transfer the jet magnetic energy to the emitting particles, thus powering the observed non-thermal emission. With 2D and 3D PIC simulations, we show that magnetic reconnection in blazar jets satisfies all the basic conditions for the emission: extended non-thermal particle distributions (with power-law slope between -2 and -1), efficient dissipation and rough equipartition between particles and magnetic field in the emitting region.

TeV photons emitted by the highest energy electrons accelerated by reconnection will interact in the intergalactic medium (IGM) with the extragalactic background light, producing a dilute beam of ultra-relativistic pairs. It is a matter of recent debate whether the energy of the pair beam is lost due to inverse Compton scattering off the CMB -- resulting in ~10-100 GeV photons -- or heats the IGM via collective plasma instabilities. The astrophysical stakes are very high because of the large amount of energy and extensive cosmic volume involved in this process. We study the relaxation of blazar-induced beams in the IGM, by means of 2D and 3D PIC simulations. We find that at most 10% of the beam energy is deposited into the IGM plasma, so that at least 90% of the beam energy will be ultimately re-processed in the multi-GeV band.

Darby Dyar (Mt. Holyoke College)

Sept. 17, 2015, 3:45 p.m. — 1033 LGRT
Title: Laser-Induced Breakdown Spectroscopy on Mars: The Long Road towa

Abstract: Laser-induced breakdown spectroscopy (LIBS) is being used almost daily on Mars by the ChemCam instrument on the Curiosity rover. The technique uses UV, VIS, and VNIR atomic emission spectra of surface rocks and soils to quantify elemental abundances. Because only 67 standards were run on the flight instrument before launch, calibration efforts are still ongoing. LIBS is different from other types of spectroscopy because atoms interact in the plasma, such that the ratio of intensity or area of an emission line to the abundance of the element producing that line is not a direct correlation. Thus LIBS quantitative analysis is complicated by chemical matrix effects related to abundances of neutral and ionized species in the plasma, collisional interactions within plasma, laser-to-sample coupling efficiency, and self-absorption. Atmospheric composition and pressure also influence plasma intensity. This talk will detail our group's contributions to calibrating Chemcam data, both through dramatic expansion of the laboratory calibration database and development of advanced machine learning tools for their analysis. We find that many previously-unappreciated steps in spectral processing, such as baseline/continuum removal, wavelength calibration, and normalization, have dramatic effects on prediction accuracy; many of these new insights have broader applications to other types of spectroscopy as well.

Anna Sajina (Tufts University)

Sept. 10, 2015, 3:45 p.m. — 1033 LGRT
Title: Modelling dusty galaxies

Abstract: I will present current work on comparing GADGET+Sunrise hydrodynamic simulations with observations of IR-luminous galaxies at z~0.3-3. I will especially focus on the relative roles of stars and AGN in heating the dust, the role of merger stage on the emergent SED, and the most likely initial gas fractions of the merger progenitors. In all cases, I will compare the results of the simulations with earlier, more direct, measurements. I will address the successes and limitations of the current generation of hydrodynamic simulations.

Meredith Hughes (Wesleyan University)

April 23, 2015, 3:45 p.m. — LGRT 1033
Title: Circumstellar disks and planet formation with ALMA

Abstract: Circumstellar disks provide the raw material and initial conditions for planet formation. Millimeter-wavelength interferometry is a powerful tool for studying gas and dust in planet-forming regions, and it is undergoing an immense leap in sophistication with the advent of the ALMA interferometer. I will discuss some ways in which we are using millimeter-wavelength interferometry to study the process of planet formation in circumstellar disks, with particular emphasis on the kinematics of turbulence in protoplanetary disks and the surprising presence of gas in debris disks around main-sequence stars.

Tracy Webb (McGill University)

April 16, 2015, 3:45 p.m. — LGRT 1033
Title: The Growth of the Most Massive Galaxies in the Highest Density R

Abstract: The most massive galaxies in the local universe reside at the centres of galaxy clusters. Often called Brightest Cluster Galaxies (BCGs), they exhibit, as a class, highly uniform properties and are distinct from the general galaxy population. This suggests formation processes which are themselves distinct from those which dominate in massive galaxies outside of cluster cores. The mass growth of BCGs is likely linked to the overall physics of hierarchical structure formation on galaxy cluster scales, including the fundamental processes of gas cooling, star formation, energy feedback and galaxy mergers, at the centers of giant dark matter halos.

In this talk I will present new results from the largest study of high-redshift BCGs conducted to date, drawn from the SpARCS optical/NIR cluster survey. Using archival infrared data we show the star formation rate within BCGs increases to z~2, and can add as much mass to the BCG population as the previous standard model of growth by dry mergers. At low redshifts, and in X-ray/SZ selected clusters, the rare examples of star forming BCGs appear to be fed by large-scale cooling flows. However, the first of the SpARCS systems we have studied in detail, SpARCS1049, has revealed a very different phenomenon - a train-wreck of a galaxy merger at the center of the cluster. This is the first example of such a process in high-redshift cluster cores and may represent a new phase of BCG evolution, previously unaccounted for.

Pieter van Dokkum (Yale University)

April 9, 2015, 3:45 p.m. — LGRT 1033
Title: A history of the dense cores of massive galaxies over the past

Abstract: Owing to several large surveys with new instruments on HST we are now able to measure the basic properties of galaxies over most of cosmic history. This talk will highlight one such survey, 3D-HST, which has obtained spectra and images of many thousands of faint galaxies. I will also discuss the next step, that is, how to reconstruct the histories of different kinds of galaxies from this wealth of data. This reconstruction has now been done for galaxies like the Milky Way, enabling us to look at "baby pictures" of galaxies like our own.

Katja Poppenhaeger (CfA)

April 2, 2015, 3:45 p.m. — LGRT 1033
Title: A high-energy view of exoplanets and their host stars

Abstract: Many exoplanets orbit their host stars at close distances, with orbital periods of only a few days. For such systems, the magnetic activity of the planet-hosting star determines the high-energy environment of its exoplanet and is an important factor in understanding the exoplanetary evolution. X-ray and UV observations allow us to determine the high-energy input into the exoplanetary atmosphere, which is the main driver of planetary evaporation. X-ray emission is also directly connected to the stellar rotation; without external input of angular momentum, the star spins down over time due to magnetic braking. However, if there is tidal interaction between a star and its Hot Jupiter, the spin-down of the host star may not follow the usual age/rotation/activity relations. I will discuss recent X-ray and UV observations which provide insights into both the evaporation of close-in exoplanets and a possibly altered age-activity relationship for host stars of such planets.

Rob Simcoe (MIT)

March 26, 2015, 3:45 p.m. — LGRT 1033
Title: Heavy Element Enrichment in Early Intergalactic and Circumgalact

Abstract: Infrared photometric surveys are discovering numerous quasars at z > 6.5, enabling absorption investigations of neutral Hydrogen and its associated heavy elements at the tail end of the reionization epoch. I will describe the status of my group's ongoing IR and optical spectroscopic surveys targeting metal pollution in the first few Gyr. Beginning with a systematic study of absorption candidates for "cold flows" at z~3, I will move on to describe a 100-sightline survey of circumgalactic MgII pollution with the Magellan/FIRE spectrometer, extending prior optical measurements (restricted to z<2) out to z~6.5. I will also describe our latest constraints on the CIV mass density and intergalactic carbon enrichment at z = 4.5-6.5. Finally, I will outline our first attempt at measuring actual chemical abundances in the z > 7 universe, and discuss their significance for reionization and the formation of the first stars.

Beth Willman (Haverford)

March 12, 2015, 3:45 p.m. — LGRT 1033
Title: Triumphs and tribulations of near-field cosmology with wide-fiel

Abstract: Over the last decade, wide-field surveys have revolutionized our view of the Milky Way’s stellar halo and dwarf galaxy population. Much of this observational progress has been motivated by a series of apparent “crises” for our cosmological model: the missing satellites problem, too big to fail, and the apparent planar distribution of dwarf satellite galaxies. These challenges have effectively functioned as flashlights pointing us to interesting galaxy formation physics. I will highlight related observational progress in our understanding of galaxy formation using near-field observations. I will then focus on the limiting impacts of observational bias and ways that current and future surveys will be used to tackle these biases. In particular, I will present new predictions for the number of Milky Way dwarf galaxies expected to be discovered in DES and LSST, RR Lyrae stars as a tool to discover dwarf galaxies in previously unexplored territory, and the use of M giant stars to map the Milky Way’s halo beyond its virial radius.

Elizabeth Blanton (Boston University)

March 5, 2015, 3:45 p.m. — LGRT 1033
Title: Extragalactic Jets as Probes of Clusters of Galaxies

Abstract: I will present multi-wavelength (X-ray, optical, infrared, and radio) observations of clusters of galaxies, including in-depth study of nearby objects and a survey of distant systems. Cooling of the hot intracluster medium in cluster centers can feed the supermassive black holes in the cores of the dominant cluster galaxies leading to AGN outbursts. This AGN feedback can reheat the gas, stopping cooling and large amounts of star formation. Most relaxed, cool core clusters host powerful AGN in their central galaxies and these AGN can significantly affect the distribution of e.g., temperature and abundance on cluster scales. AGN heating can come in the form of shocks, buoyantly rising bubbles that have been inflated by radio jets and lobes, and sound wave propogation. Sloshing of the cluster gas, related to minor, off-center interactions with galaxy sub-clusters or groups also affects the distribution of temperature and abundance on large scales. This sloshing gas can interact with the AGN's radio-emitting jets and lobes causing them to bend. This bending is also found in AGN jets and lobes embedded in clusters undergoing major, head-on cluster, cluster mergers. Since this bending is a signature of interaction within clusters, bent, double-lobed AGN observed in the radio can be used as beacons for clusters of galaxies at high redshifts. I will describe our large sample of high-redshift, bent-double radio sources that were observed in the infrared with Spitzer and that have yielded approximately 200 new, distant clusters of galaxies with z > 0.7. These clusters will serve as important laboratories for studying galaxy evolution and cosmology.

Andrey Kravtsov (University of Chicago)

Feb. 26, 2015, 3:45 p.m. — LGRT 1033
Title: Order out of chaos: formation of galaxies in hierarchical univer

Abstract: Galaxy formation is a complex, hierarchical, highly non-linear process, which involves gravitational collapse of dark matter and baryons, supersonic, highly compressible and turbulent flows of gas, star formation, stellar feedback, as well as heating, cooling, and chemical processes. All of these processes appear to be critically important in shaping properties of galaxies. At the same time, despite the apparent complexity of these processes and the ways they interact, observed properties of galaxies exhibit a number of striking regularities, such as tight correlations between galaxy sizes, masses, luminosities, and internal velocities and surprisingly tight correlations between properties of stars and gas in galaxies and the mass and extent of their parent halos dominated by dark matter. Existence of such correlations indicates that powerful processes operate to bring order out of chaos. In this talk I will discuss some insights based on the recent work aimed to understand this aspect of galaxy formation, focusing on some specific issues in how mass of galaxies and their host dark matter halos is assembled and in how thermodynamics processes of diffuse gas, star formation, and stellar feedback conspire to produce galaxies quite close to observed systems.

Jill Naiman (CfA)

Feb. 19, 2015, 3:45 p.m. — LGRT 1033
Title: Gas Retention and Accumulation in Dwarf Galaxies: Implications f

Abstract: The effective supply and retention of gas in shallow gravitational potentials is a problem with implications in a diverse set of astrophysical systems. In particular, the magnitude of gas flows into mature dwarf galaxies can have large impacts on the star formation histories in these systems. In this talk, computational techniques will be used to show how such such weakly bound gravitational structures might be able to accumulate gas effectively. The implications for star formation in dwarf galaxies after their incorporation into a larger host halo will be presented.

Blakesley Burkhart (CfA)

Feb. 12, 2015, 3:45 p.m. — LGRT 1033
Title: New Frontiers of Magnetized Turbulence in the Multiphase Interst

Abstract: New Frontiers of Magnetized Turbulence in the Multiphase Interstellar Medium

The current paradigm of the ISM is that it is a multiphase turbulent environment, with turbulence affecting many important processes. For the ISM this includes star formation, cosmic ray acceleration, and the evolution of structure in the diffuse ISM. This makes it important to study interstellar turbulence using the strengths of numerical studies combined with observational studies. I shall discuss progress that has been made in the development of new techniques for comparing observational data with numerical MHD simulations in the star forming molecular medium and in neutral gas as traced by 21 cm emission.

Brice Menard (JHU)

Feb. 5, 2015, 3:45 p.m. — LGRT 1033
Title: De-projecting astronomical surveys

Abstract: Observations of the sky are inherently a 2-dimensional measurement of flux density on the sphere of the sky. For astrophysical studies, however, one usually needs the knowledge of 3d positions, for example to convert an angle into a physical scale or a brightness into a luminosity. In the context of extragalactic surveys, distance or redshift information is usually done with "photometric redshifts", which rely on strong assumptions and often lead to problematic estimates. In this talk I will how it is possible to instead use clustering measurements and infer redshifts for any type of extragalactic sources. I will show applications of this "clustering-redshift" technique to various datasets at UV, optical, IR and radio wavelengths, and show a number of surprises.

Anne Jaskot (Smith/UMass/Five College Astronomy Department)

Jan. 29, 2015, 3:45 p.m. — LGRT 1033
Title: HI, Stars, and Ionizing Photons: Gas Cycles and LyC Escape in Lo

Abstract: Neutral hydrogen gas plays a key role in galaxy evolution, by both providing the raw material for star formation and responding to the resulting stellar feedback. Two samples of low-redshift starburst galaxies, ALFALFA H-alpha and the Green Peas, give new insights into the relationship between HI gas, star formation, and UV radiation. Using 565 starburst and non-starburst galaxies from the HI-selected ALFALFA H-alpha survey, I will analyze the role of the HI gas supply in driving high levels of star formation and discuss factors that may promote efficient HI to H2 conversion. With both ground-based and HST observations of the Green Pea galaxies, some of the most extreme low-mass starbursts in the nearby universe, I will focus on the propagation of ionizing radiation through the neutral gas. In particular, the Green Peas may be leaking ionizing radiation into the intergalactic medium and are therefore potential analogs of the galaxies responsible for cosmic reionization.

Josh Shiode, John N. Bahcall Public Policy Fellow (American Astronomical Society)

Jan. 22, 2015, 3:45 p.m. — LGRT 1033
Title: There's Government in Your Science

Abstract: The majority of basic science research in the United States — including that in the astronomical sciences — is funded by the federal government. This is both good and bad. Good because there are a lot of resources available, though basic research funding is but a small fraction of the total federal budget. Bad because individual scientific projects, and the careers of the scientists involved, can be affected by political winds they would otherwise never feel. In this talk, I’ll try to convey a sense of those winds. I’ll focus on the process of policymaking and long-term trends relevant to the scientific enterprise, and we’ll explore how individual scientists and science advocates can play a role in the political and policymaking process.

Kaitlin Kratter (University of Arizona)

Dec. 11, 2014, 3:45 p.m. — LGRT 1033
Title: What can we learn from planets in binary systems?

Abstract: Exoplanet surveys have revealed a surprising array of planetary systems hosted by binary stars. The diversity and architecture of these systems provide insight into the fundamentals of planet formation for a wide range of systems. Moreover, these planets provide an important final boundary condition for our models of star formation, and especially binary formation. I will review the statistics of these surprisingly un-exotic systems, describe the theoretical implications, and discuss the prospects for progress with observational facilities of the future.

Stephanie LaMassa (Yale University)

Dec. 4, 2014, 3:45 p.m. — LGRT 1033
Title: Discovering Rare AGN with the Stripe 82X X-ray Survey

Abstract: Supermassive black holes (SMBHs) grow by accreting matter in a phase where they are observed as active galactic nuclei (AGN). In order to track the evolution of rare objects, such as AGN at high luminosity, which signal when the majority of black hole growth occurred, a large volume of the Universe has to be explored through wide area surveys. Until recently, no large area X-ray survey has existed, meaning that a key phase in SMBH growth and SMBH/galaxy co-evolution is missing: luminous obscured SMBH growth. To rectify this gap, I have begun a wide area X-ray survey in the Sloan Digital Sky Survey region Stripe 82 which contains a veritable treasure trove of multi-wavelength coverage, expediting follow-up of identified X-ray sources. In this talk, I will review the highlights of our first release of "Stripe 82X" which covers ~16.5 deg^2 with ~3300 X-ray sources identified. I will discuss our current ground-based follow-up campaigns to target interesting classes of AGN and will comment on what we expect to learn with the addition of 20 deg^2 awarded to our team in the current XMM-Newton observing cycle.

Mike Dunham (CfA)

Nov. 20, 2014, 3:45 p.m. — LGRT 1033
Title: The Evolution of Protostars: Assembling Stars from Dense Cores

Abstract: Stars form from the gravitational collapse of dense molecular cloud cores. In the protostellar phase, mass accretes from the core onto a protostar, likely through an accretion disk, and it is during this phase that the initial masses of stars and the initial conditions for planet formation are set. Over the past decade, new observational capabilities have provided wide-field infrared and (sub)millimeter surveys of entire star-forming clouds along with interferometric images at very high angular resolution, giving an unprecedented view of the star formation process. In this talk I will review resulting advances in the field of protostellar evolution, focusing on observational constraints on the problem of how mass is transferred from dense cores to stars.

Nick Cowan (Amherst College)

Nov. 13, 2014, 3:45 p.m. — LGRT 1033
Title: Balancing the Radiation Budget of Short-Period Planets

Abstract: What started as a trickle in the mid 1990’s is now a torrent, with over one thousand extrasolar planets currently known, and thousands of candidates awaiting confirmation. The study of exoplanets has already revolutionized our view of planet formation, and will soon do the same to our understanding of planetary atmospheres and interiors. Since we view them from the top-down, one of the first aspects of exoplanet atmospheres to be constrained is their thermal emission. By combining infrared emission measurements at a variety of orbital phases, we can infer a planet's Bond albedo, the efficiency of its day-night heat transport, and, in the case of planets subject to eccentricity seasons, its thermal inertia. Multi-wavelength emission measurements can also constrain a planetary atmosphere's composition and vertical temperature structure. Such inferences are particularly sensitive to the uncertainty in emission measurements, however, and the accuracy of eclipse measurements has typically been over-stated. Fortunately, improved analysis techniques and next-generation instruments should allow us to resolve outstanding questions about hot Jupiters, and to extend our methods to temperate terrestrial planets.

Erik Tollerud (Yale University)

Nov. 6, 2014, 3:45 p.m. — LGRT 1033
Title: Local Dwarf Galaxies and Near-Field Cosmology in ΛCDM

Abstract: Dwarf galaxies are a frontier for new discoveries in both galaxy formation and cosmology. I discuss work centered around connecting LCDM and its predictions to observations of dwarf galaxies at three different scales of "dwarf". I will discuss the Milky Way's satellites and both solutions and lingering troubles with their abundances and scalings. The strangest of these puzzles manifest in the bright dSphs, which seem to be under-dense relative to LCDM expectations. With this in mind, I describe results from a large spectroscopic survey of M31's dSph satellites searching for signs of similar puzzles. Finally, I describe searches for comparable satellites beyond the Local Group, and compare their abundances and properties to straightforward LCDM expectations.

Scott Chapman (Dalhousie University)

Oct. 30, 2014, 3:45 p.m. — LGRT 1033
Title: The role of ultra-luminous galaxies in galaxy formation and evol

Abstract: I will provide an overview of ultra-luminous galaxies (L_IR>1012 Lsun) at high redshift, and the different roles and properties they appear to exhibit as a function of their luminosity. I will focus on the molecular gas properties of the galaxies as the crucial fuel available for star formation, emphasizing our recent work with ALMA and the IRAM Plateau-de-Bure, where we have studied galaxies preselected at various wavelengths, and conducted blind surveys for CO gas. I will conclude with very wide field surveys (SPT) that are uncovering the most extreme specimens of star forming galaxies in the universe, and point to future facilities like CCAT which will push the field to a new level of understanding.

Greg Stinson (MPIA)

Oct. 23, 2014, 3:45 p.m. — LGRT 1033
Title: A Critical Phase in Galaxy Formation

Abstract: As galaxies grow and evolve, they go through a violent phase of their evolution where intense star formation drives outflows. I will examine this phase using cosmological galaxy formation simulations. The simulations show that starbursts and outflows have implications for many observed properties of galaxies including their gaseous halos, morphology, potential, and star formation history.

Laura Lopez (MIT)

Oct. 16, 2014, 3:45 p.m. — LGRT 1033
Title: Observational Assessment of Stellar Feedback in Star-Forming Reg

Abstract: Stellar feedback has a profound influence in many astrophysical phenomena, yet it is often cited as one of the biggest uncertainties in star and galaxy formation models today. This uncertainty stems from a dearth of observational constraints as well as the great dynamic range between the small scales (<1 pc) over which feedback occurs and the large scales (>1 kpc) on which galaxies are shaped by that feedback. In this talk, I will show how multiwavelength observations can be used to overcome these challenges to assess the role of many stellar feedback mechanisms, including radiation, stellar winds, supernovae, and cosmic rays. I will present results from the application of these approaches to a variety of sources and discuss the implications regarding the dynamics of star-forming regions and the launching of galactic winds. Finally, I will highlight the exciting prospects of using current and upcoming facilities to explore feedback in diverse conditions.

Mario Livio (STScl)

Oct. 9, 2014, 3:45 p.m. — ILC S140
Title: Brilliant Blunders

Abstract: Even the greatest scientists have made some serious blunders. "Brilliant Blunders" concerns the evolution of life on Earth, of the Earth itself, of stars, and of the universe as a whole. In this talk, I shall concentrate on and analyze major errors committed by such luminaries as Charles Darwin, Linus Pauling, and Albert Einstein. I will also scrutinize the various types of blunders and attempt to identify their causes. Most importantly, however, I'll argue that blunders are not only inevitable, ­but rather part and parcel of progress in science and other creative enterprises.

Andrew West (Boston University)

Oct. 2, 2014, 3:45 p.m. — LGRT 1033
Title: Stellar Underdogs: the Comeback of Low-mass Stars in the Era of

Abstract: My primary goal of this colloquium is to demonstrate that we can do big science with little stars. M and L dwarfs are the smallest, coolest and least massive (main sequence) stars in the Galaxy. Yet despite their diminutive physical properties, low-mass stars make up ~70% of all of the stars in the Milky Way galaxy and have lifetimes that exceed trillions of years. Their dominance in the Galaxy make low-mass stars excellent tracers of both the structure and evolution of the local Milky Way. In addition, low-mass stars have intense stellar flares and strong magnetic fields that allow us to probe their interiors and may have important consequences for their space weather environments and the habitability of planets that orbit them. I will present results from the largest samples of low-mass stars ever assembled. The advent of large surveys such as the Sloan Digital Sky Survey (SDSS) has yielded photometric and spectroscopic catalogs of more than 100 million and 70,000 stars respectively. Specifically, I will highlight work that has used the unprecedented statistical power of surveys to examine the nature of stellar magnetic fields (and subsequent "magnetic activity") and stellar age, and how large samples of wide low-mass binaries can help us constrain evolutionary models of stars. In addition, I will highlight the confirmation of an age-rotation-activity relation that has come from a collaboration with the MEarth planet hunting team, show how IR excesses around low-mass dwarfs may give us insights into planet formation/evolution, and demonstrate how a large sample of M dwarfs has helped us map the three-dimensional distribution of dust in the local Galaxy.

Debra Fischer (Yale University)

Sept. 25, 2014, 3:45 p.m. — LGRT 1033
Title: The Search for 100 Earths

Abstract: The search for exoplanets is motivated by the question of whether life exists elsewhere. This drives our interest in the detection of planets that are similar to our own world: rocky planets with the potential for liquid surface water and plate tectonics; worlds that might harbor life that we can recognize. Importantly, we will need to discover not just a few, but hundreds of these worlds to eventually gain a statistical understanding of whether life is rare, common, or ubiquitous and ground-based telescopes offer an ideal platform for carrying out decade-long surveys. It is critical for follow-up studies (imaging, atmospheric studies) that these planets orbit nearby stars. In this talk, I will discuss how we plan to take what we've learned and push on to the next frontier: our plans for a next generation spectrograph, EXPRES, to carry out a search 100 Earths with the Discovery Channel Telescope.

Jason Tumlinson (STScl)

Sept. 18, 2014, 3:45 p.m. — LGRT 1033
Title: The Circumgalactic Medium: A New Window on Galactic Fueling, Que

Abstract: Why do some galaxies quench while others continue to form stars? Where is all the normal matter that galaxies should have, but don't? What happens to all the heavy elements that stars produce? The gas flows that feed galaxies and return their enriched products back to their environments are arguably the most important and least understood processes driving galaxy evolution. I will survey our group's results from Hubble's Cosmic Origins Spectrograph on the diffuse "Circumgalactic Medium" surrounding galaxies that reveal it to be a massive and richly structured medium with important roles as the mediator of galaxy accretion and feedback and a potential answer to some of these open questions about galaxies.

Jeff Wagg (SKA)

Sept. 11, 2014, 3:45 p.m. — LGRT 1033
Title: From Exoplanets to Cosmic Dawn with the Square Kilometre Array

Abstract: Building on the major scientific advances made by the current generation of cm and metre-wavelength telescopes, phase 1 of the Square Kilometre Array (SKA) will be the next global radio astronomy observatory. The SKA is being designed by more than 350 engineers and scientists from around the world, with the aim to begin early science operations in 2020. The SKA will answer fundamental questions related to the evolution of atomic Hydrogen in the Universe, from the present day back to the Cosmic Dawn, when the first galaxies began to form less than 200 Myr after the Big Bang. It will also conduct key tests of general relativity through surveys and timing of pulsars in our galaxy, and beyond. I will give an overview of some of the science drivers for the SKA, along with a description of the planned SKA telescopes and the sites that will host them.

Thaisa Storchi-Bergmann (Universidade Federal do Rio Grando do Sul)

Sept. 4, 2014, 3:45 p.m. — LGRT 1033
Title: Feeding & Feedback of Supermassive Black Holes tracing Co-evolut

Abstract: A fundamental role is attributed to supermassive black holes (SMBH) and the feedback they generate in the evolution of galaxies. Cosmologial models that do not consider these feedback effects end up
producing over-massive galaxies. I will present and discuss astronomical observations of feeding and feedback processes around SMBHs that occur when the SMBH is being fed in Active Galactic Nuclei
(AGN). These observations comprise optical and near-infrared Integral Field Spectroscopy of the inner few hundred parsecs of nearby AGN host galaxies, and are intended to provide constraints to the feeding and feedback processes. I will discuss in particular results obtained by my group that reveal gas inflows along nuclear spirals and disks. The inflow rates are much larger than the AGN accretion rate, suggesting that the excess gas is depleted via formation of new stars that are indeed observed in many casas and can be interpreted as signatures of co-evolution of the host galaxy and its AGN. Gas outflows are prevalent among the highest luminosity AGN, with velocities ranging from a few up to ~1000 km/s and mass outflow rates of a few solar masses per year.

Andy Fruchter (STScI)

May 1, 2014, 3:45 p.m. — LGRT 1033
Title: Refusing to Go Quietly: Gamma-Ray Bursts and their Progenitors

Abstract: Gamma-ray bursts (GRBs) are the most brilliant objects in the universe. Some are initially bright enough to be seen by the unaided eye across a distance of billions of light years. Yet the majority of GRBs which are detected, the so-called long-soft GRBs (LGRBs) are, like most supernovae, produced by the collapse of a massive star. I will discuss the environmental conditions that appear to produce LGRBs, and what this tells us about their progenitor stars. I will also speak about the less frequently detected and even more poorly understood, "short-hard" GRBs (SGRBs), and present recent observations which appear to show a "kilonova" associated with SGRB 130603B. If this interpretation of the data is also supported by observations of future bursts, it will provide direct evidence that SGRBs are formed by the merger of compact objects, and give us an electromagnetic signature that could help locate sources of gravitational waves in the advanced-LIGO era.

Claudia Scarlata (Univ. of Minnesota)

April 17, 2014, 3:45 p.m. — LGRT 1033
Title: The WISP survey: overview of recent results for galaxies in the

Abstract: The WFC3 Infrared Spectroscopic Parallel Survey (WISP) is a large ( ~1000 orbits) HST program that uses WFC3 slitless spectroscopy to detect thousands of galaxies across a wide redshift range 0.3 < z < 2.3. I will present an overview of recent results on emission line galaxies, including a statistical determination of their dust extinction properties, the discovery of a new population of extremely strong emission-line dwarf galaxies, and the implication of the observed number counts for the EUCLID mission. I will also discuss the properties of passive galaxies at z∼1.5 derived from the combination of the WISP spectra with broad-band photometry from HST-UVIS and Spitzer images.

Arjun Dey (NOAO)

April 10, 2014, 3:45 p.m. — LGRT 1033
Title: Lyman Alpha Emission and Galaxy Formation: An Observer's Perspec

Abstract: Lyman alpha has long been used as a signpost of young galaxies in the distant Universe. My collaborators and I are engaged in ongoing searches for Lyman alpha emission at a range of redshifts (z~2-4), discovering both Lyman alpha "blobs" (giant, 100-kpc clouds of glowing, galaxy-forming gas) and much lower mass Lyman alpha emitters, which may be the building blocks of larger galaxies. I will also discuss some of the properties of the new blobs (one of which is a good candidate for an extremely low-metallicity galaxy forming environment) and report on using Lyman alpha as a tracer of protocluster environments at high redshift.I will also talk briefly about the DESI project planned for the Mayall telescope, a cost-effective dark energy project for this decade. I will describe the main scientific goals, the technical plan and the current status of this project.

Jeff Newman (University of Pittsburgh)

April 3, 2014, 3:45 p.m. — LGRT 1033
Title: Exploring the Milky Way and the Universe with Extragalactic Surv

Abstract: Determining the global properties of the Milky Way presents unique challenges, primarily due to our position embedded within its disk. As a result our knowledge of many basic properties of the Galaxy, including itscolor and luminosity, has remained limited. In this talk, I will describe how we have developed improved determinations of the total stellar mass (M) and star formation rate (SFR) of the Milky Way using Hierarchical Bayesian statistical techniques. We then use the results, in combination with data from SDSS, to better determine the Galaxy's luminosity and integrated color. We exploit the close relationship between galaxies' photometric properties and their total stellar mass and star formation rate. We thus select a sample of Milky Way analog galaxies designed to match the best Galactic M and SFR measurements, including measurement uncertainties. Applying the Copernican assumption that the Milky Way should not be special amongst galaxies of similar properties, the color and luminosity distribution of these Galactic analogs then constrains the properties of our own Galaxy much more tightly than previous measurements. In the remaining time, I will describe the next steps in large spectroscopic surveys of the distant universe. I will provide an overview of the eBOSS project, a component of the next-generation SDSS-IV survey beginning observations this summer; eBOSS will obtain redshifts of ~650,000 galaxies and ~850,000 QSOs at 0.6 < z < 3.5 in order to study dark energy via the Baryon Acoustic Oscillations (BAO) technique. I will also describe plans for DESI, the Dark Energy Spectroscopic Instrument, which may be used for a survey of >20 million galaxies and QSOs, placing strong constraints on dark energy models via BAO early in the next decade.

Scott Chapman (Dalhousie University)

March 27, 2014, 3:45 p.m. — LGRT 1033
Title: The role of ultra-luminous galaxies in galaxy formation and evo

Abstract: I will provide an overview of ultra-luminous galaxies (L_IR>1012 Lsun) at high redshift, and the different roles and properties they appear to exhibit as a function of their luminosity. I will focus on the molecular gas properties of the galaxies as the crucial fuel available for star formation, emphasizing our recent work with ALMA and the IRAM Plateau-de-Bure, where we have studied galaxies preselected at various wavelengths, and conducted blind surveys for CO gas. I will conclude with very wide field surveys (SPT) that are uncovering the most extreme specimens of star forming galaxies in the universe, and point to future facilities like CCAT which will push the field to a new level of understanding.

Pete Schloerb (UMass)

March 13, 2014, 3:45 p.m. — LGRT 1033
Title: Update on the Large Millimeter Telescope

Abstract: I will provide an update on the status of the Large Millimeter Telescope. The LMT has begun a second season of "Early Science" observations with its new active surface system in place. The telescope and instruments are working well, and our understanding of the system and its performance have improved greatly over the past year. All in all, things are in good shape, and we have a millimeter-wave telescope that is very competitive with the world's other large millimeter-wave single dish telescopes. I will review the technical performance of the LMT and present some examples of scientific data obtained with the telescope. Then we will turn our attention to the future and present an overview of the completion plan for the full 50m telescope. Finally we will consider the long term future of LMT Observatory and the participation of astronomers from UMass and the US community in this endeavor.

Ranga-Ram Chary (Caltech)

March 6, 2014, 3:45 p.m. — LGRT 1033
Title: CSI-Los Angeles: The Growth of Distant Galaxies and Reionization

Abstract: The discovery of an unusual population of galaxies with extremely strong nebular line emission has come as a panacea to several problems in galaxy evolution. These objects, classified as Halpha emitters, were first detected in the z>5 Universe in deep Spitzer imaging, where they dominate the spectroscopically confirmed star-forming galaxy population. Since then, they have been re-discovered in the local Universe in the Sloan Digital Sky Survey where they constitute 0.04% of the spectroscopic sample, and at intermediate redshifts using Hubble/WFC3 grism surveys. Their ubiquity in the distant Universe and the unusual properties of their stellar population make them strong candidates for being progenitors of massive galaxies at z~2 and for being the primary sources responsible for reionization. I will present our work in identifying these galaxies, insights into the mechanism for fueling star-formation in these objects and the resultant reionization history of the Universe. The merits of using multiwavelength observations in obtaining an improved understanding of high redshift galaxy populations will in particular be highlighted.

Junko Ueda (University of Tokyo and CfA)

Feb. 27, 2014, 3:45 p.m. — LGRT 1033
Title: Probing the evolution of merger remnants through formation of c

Abstract: It has been long predicted from numerical simulations that a major merger of two disk galaxies results in a formation of the spheroid-dominated early-type galaxy. Contrary to this classical scenario of galaxy merger evolution, recent simulations with more realistic gas physics have shown that not all of the major mergers will become an early-type galaxy, but some will reemerge as a disk dominated late-type galaxy. In order to check this scenario and look for observational evidence of a forming molecular disk, we investigate new and archival interferometric CO maps of 37 optically selected merger remnants in the local universe. The new maps are obtained toward 27 sources with ALMA, CARMA, and SMA. We find that 65 % (24/37) of the sample show kinematical signatures of the molecular gas disk in their velocity fields. However, the majority of the merger remnants except for a few shows a compact molecular gas disk relative to the stellar spheroidal component. Unless the disks grow significantly, for example from the return of ejected molecular gas or tidal HI gas, the majority will likely evolve into spheroid dominated early-type galaxies. We tentatively suggest that a few sources with extended gas disks may evolve into disk dominated late-type galaxies, if there are no further mechanism to transport the molecular gas toward the central region.

Joan Najita (NOAO, CfA)

Feb. 20, 2014, 3:45 p.m. — LGRT 1033
Title: From Planetesimals to Giant Planets: Chemical and Dynamical Pro

Abstract: Work with the Spitzer Space Telescope revealed that emission from water and organic molecules is commonly present in the mid-infrared spectra of disks surrounding young stars. I will describe how these features might be used to help lift the veil on a very early stage of planet formation, the formation of planetesimals, those theoretically fundamental but observationally elusive building blocks of planets in core accretion theory. I will also describe some results from high resolution spectroscopy that suggest that forming high-mass giant planets may reveal themselves through non-axisymmetric signatures of their presence, e.g., circumplanetary disks and eccentric inner rims.

Bethany Ehlmann (Caltech (joint with Physics))

Feb. 12, 2014, 4 p.m. — Hasbrouck 124
Title: Following the Water on Mars, Roving with Curiosity

Abstract: The last decade of Mars exploration with orbiters and rovers has revealed that liquid water was common during the first billion years of the planet's history with diverse aqueous, potentially habitable environments varying in space and time. Curiosity's landing in 2012 provides the opportunity to explore one set of these environments up-close: sedimentary deposits in 150-km Gale Crater. The 10-instrument suite on Curiosity is the most advanced sent to a planetary surface to date, and results from the first year and a half of exploration will be described, along with a look ahead to the coming years as Curiosity's trek continues.

Jason Tumlinson (STScI)

Feb. 6, 2014, 3:45 p.m. — LGRT 1033
Title: The Circumgalactic Medium: A New Window on Galactic Fueling, Que

Abstract: Why do some galaxies quench while others continue to form stars? Where is all the normal matter that galaxies should have, but don't? What happens to all the heavy elements that stars produce? The gas flows that feed galaxies and return their enriched products back to their environments are arguably the most important and least understood processes driving galaxy evolution. I will survey our group's results from Hubble's Cosmic Origins Spectrograph on the diffuse "Circumgalactic Medium" surrounding galaxies that reveal it to be a massive and richly structured medium with important roles as the mediator of galaxy accretion and feedback and a potential answer to some of these open questions about galaxies.

Christine Wilson (McMaster University)

Jan. 30, 2014, 3:45 p.m. — LGRT 1033
Title: Gas and Star Formation in Nearby Galaxies: New Results From the

Abstract: The availability of new instruments and telescopes is making it possible to study large, well-selected samples of nearby galaxies at millimeter and submillimeter wavelengths. These observations trace the cold, dense gas and dust which is the fuel for star formation. I will discuss new results from the Herschel Space Observatory from the Very Nearby Galaxies Survey, which aims to observe the closest example of each major class of galaxy with all the photometric and spectroscopic modes that Herschel has available. Our results include evidence for the primary heating source of much of the dust emission in normal galaxies, an increase in the gas to dust ratio in the vicinity of the central engine in Centaurus A, and a component of very hot molecular gas seen via high frequency CO emission lines that dominates the CO luminosity of starburst and merging galaxies.

Kate Rubin (CfA)

Dec. 12, 2013, 3:45 p.m. — LGRT 1033
Title: The Gaseous Environments of Low-Mass Galaxies at z~2

Abstract: The environments extending several hundred kiloparsecs from galaxies both contain the fuel that feeds galactic star formation as well as act as the reservoir into which ejecta from stellar and AGN feedback are driven. Observations of the cool hydrogen and metal content of these regions (i.e., the circumgalactic medium, or CGM) can therefore provide incisive tests of our understanding of these processes. I will briefly discuss current constraints on the content of the CGM around massive Lyman Break Galaxies and QSO hosts at z~2. I will then describe a new technique that pinpoints much fainter, sub-luminous systems at this epoch, allowing us to probe the gas in their surroundings in absorption toward background QSOs for the first time. These measurements reveal the incidence and spatial distribution of the cool HI and metal enrichment in the lowest-mass halos at the peak of cosmic star formation activity.

Christine Chen (STScI)

Dec. 5, 2013, 3:45 p.m. — LGRT 1033
Title: The Origin and Evolution of Dust and Gas in Debris Disks

Abstract: Debris disks are dusty, gas-poor disks around young stars, generated by collisions between parent bodies and/or sublimation of comets. The Spitzer Space Telescope has enabled photometric searches and detailed spectroscopic studies of thermal emission from dust in hundreds of debris disks at mid- to far-infrared wavelengths. These observations allow us: (1) to infer the spatial structure of dust in individual systems and determine how the dust grains are removed; (2) to measure the disk fraction (in young associations and moving groups) as a function of age to constrain the mechanism that triggers collisions; and (3) to place constraints on the mass of circumstellar molecular hydrogen and therefore models for giant planet formation. In this talk, I will discuss the spatial structure and removal mechanisms of dust in debris disks, and constraints on the models for the formation of gas giants and the late-stages of solar system evolution. I will also describe outstanding questions about debris disk evolution that will be addressed using future ground- and space-based instruments.

Thanksgiving recess ( )

Nov. 28, 2013, 3:45 p.m. — LGRT 1033
Title:

Dominik Riechers (Cornell)

Nov. 21, 2013, 3:45 p.m. — LGRT 1033
Title: Fueling Cosmic Star Formation: The Molecular Interstellar Medium

Abstract: Submillimeter galaxies (SMGs) are thought to represent the link between high-redshift star-forming galaxies and passive early type galaxies, with the huge merger driven bursts consuming up most of the available gas and driving the morphological transition to a spheroid. These hyper-luminous high-z galaxies commonly trace regions of high galaxy overdensity, and may be directly related to the formation of galaxy clusters and their giant central ellipticals. Molecular gas plays a central role in our understanding of the nature of these often heavily obscured systems. It represents the material that stars form out of, and its mass, distribution, excitation, and dynamics provide crucial insight into the physical processes that support the ongoing star formation and stellar mass buildup. I will discuss the most recent progress in studies of gas-rich galaxies at high redshift through large submillimeter surveys with the Herschel Space Observatory and detailed follow-up studies of the molecular gas properties of SMGs with CARMA, the Jansky Very Large Array (JVLA), the Plateau de Bure interferometer, and the Atacama Large (sub)Millimeter Array (ALMA).

Chris Hayward (Heidelberg, Germany)

Nov. 14, 2013, 3:45 p.m. — LGRT 1033
Title: Advances in galaxy-formation simulations: calculating mock obser

Abstract: Galaxy formation has been studied using idealized numerical simulations of isolated disk galaxies and galaxy mergers for decades, but most simulations performed to date have suffered from two potentially significant limitations: First, when comparing simulations with observations, physical quantities - rather than observables - from the simulations are used. Second, the most-commonly used techniques, smoothed-particle hydrodynamics (SPH) and adaptive mesh refinement, suffer from numerical inaccuracies that can potentially jeopardize the results of simulations performed with those techniques. I will discuss methods for solving both of these limitations. I address the first limitation by performing 3-D dust radiative transfer on hydrodynamical simulations to calculate spatially resolved UV-mm spectral energy distributions of simulated galaxies. I will present an application to submillimeter galaxies, for which a realistic comparison with observables yields results that are qualitatively different from those of more naive comparisons. I address the second limitation by using the more-accurate moving-mesh hydrodynamics code Arepo. I will discuss how merger simulations performed with the moving-mesh technique differ from otherwise identical simulations performed using SPH. Finally, based on this comparison and other work, I will outline the types of galaxy-formation simulations for which the traditional formulation of SPH is sufficiently accurate and describe when and why this is not the case.

Houjun Mo (UMass)

Nov. 7, 2013, 3:45 p.m. — LGRT 1033
Title: Star formation and stellar mass assembly histories in dark matte

Reka Winslow (University of British Columbia)

Oct. 31, 2013, 3:45 p.m. — LGRT 1033
Title: Investigation of Mercury's magnetospheric and surface magnetic

Abstract: Mercury’s proximity to the Sun and its low magnetic field strength lead to dynamic interactions of the solar wind with the magnetosphere as well as with the planet’s surface, which are unique in the solar system. MESSENGER, having been in orbit about Mercury since March 2011, has made important discoveries of this exciting magnetospheric environment. In this talk, I will discuss some aspects of Mercury’s magnetosphere, paying special attention to the bow shock, magnetopause, and cusp regions as well as to the planet’s internal magnetic field. I will discuss how we characterized the time-averaged shape and location of Mercury’s magnetopause and bow shock, as well as established these boundaries’ responses to the solar wind and interplanetary magnetic field. I will also describe the first observations of Mercury’s northern cusp region using Magnetometer data, and our estimates of the flux of precipitating particles to the surface. Finally, I will discuss a novel adaptation of the electron reflectometry technique in which we use protons precipitating to the surface (observed by the Fast Imaging Plasma Spectrometer onboard MESSENGER) to acquire the first measurements of Mercury’s surface magnetic field strength.

Marc Postman (STScI)

Oct. 24, 2013, 3:45 p.m. — LGRT 1033
Title: The Cluster Lensing And Supernova survey with Hubble (CLASH)

Abstract: The Cluster Lensing And Supernova survey with Hubble (CLASH), a 524-orbit Multi-Cycle Treasury Program, completed its observations this past July. CLASH uses the gravitational lensing properties of 25 galaxy clusters to address at least 4 key science objectives: (1) Map the dark matter distribution in clusters with unprecedented accuracy, (2) Detect type Ia supernova out to z~2 to constrain their rates, the time evolution of the dark energy equation of state and the evolution of SN Ia themselves, (3) Detect and characterize some of the most distant galaxies (z > 7), and (4) study the internal structure and evolution of the galaxies in and behind the clusters. The survey obtained broadband images of the clusters in 16 passbands, providing remarkable panchromatic coverage from 0.2 - 1.6 microns, all with HST-quality resolution. I will present highlights from each of the 4 main science objectives.

Roman Shchebarkov (Univ. of Maryland)

Oct. 17, 2013, 3:45 p.m. — LGRT 1033
Title: Feeding and Feedback in Nearby Low-luminosity AGNs.

Abstract: Most galaxies in the Universe host low-luminosity AGNs. These systems exhibit a vast range of dynamical and radiative effects, which require high sensitivity and high angular resolution to study. The closest objects with the largest central supermassive black holes are revealing their secrets with the improvement of instrumentation. I will review recent progress on observing with Chandra and modeling of the accretion flow onset regions in Sgr A* and NGC3115. The hot accretion flow in these sources is shaped by the combined effects of (1) radius-dependent mass injection by stellar winds, (2) galactic gravitational potential, (3) small-scale feedback such as conduction, and (4) supernova feedback. The natural outcomes of modeling are the virial/supervirial gas temperature and inhibited accretion with shallow density profile.

Massimo Stiavelli (STScI)

Oct. 10, 2013, 3:45 p.m. — LGRT 1033
Title: Reionization and first light studies using space telescopes: an

Abstract: I will discuss what existing data tell us about the reionization of the Universe and the role played by faint galaxies including some new results derived by constraining the faint end of the luminosity function at redshift 6 using a form of surface brightness fluctuations analysis. I will also discuss expectations for the JWST contribution in this field. Moving to higher redshift I will discuss how JWST will study the first galaxies and the constraints it could place on the first stars by studying their supernovae.

Laura Cadonati (UMass)

Oct. 3, 2013, 3:45 p.m. — LGRT 1033
Title: Progress towards gravitational wave astronomy

Abstract: The quest for gravitational waves is reaching a key milestone as Advanced LIGO is approaching completion and science runs are scheduled to begin in 2015. In this talk, I will review the status and timelines of second generation gravitational wave detectors and the prospected observing scenarios over the next decade, with focus on searches for gravitational wave transients, the ability to localize gravitational wave sources and the ongoing efforts towards coincident searches of gravitational wave and electromagnetic signatures.

Kate Whitaker (GSFC)

Sept. 26, 2013, 3:45 p.m. — LGRT 1033
Title: The Quenching of Star Formation in Massive Galaxies

Abstract: Nearby galaxies exhibit a bimodal color distribution, where actively star-forming galaxies have blue colors and quiescent galaxies have red colors. It is generally thought that red galaxies arise from blue galaxies when star formation is quenched. However, the origin of this color bimodality remains unknown. Furthermore, it is not well understood how actively star-forming galaxies quench and migrate to form the well-defined color-mass relation, known as the “red sequence”. In this talk, direct evidence is presented that the massive end of the red sequence is most-rapidly building up when the universe was only 3 billion years old, with an influx of young recently quenched galaxies that are almost non-existent over the past 8 billion years. Presenting recent results from the 3D-HST Survey, I will discuss the properties of these massive galaxies in the context of current galaxy formation and evolution theories.

Jason Kalirai (STScI)

Sept. 19, 2013, 3:45 p.m. — LGRT 1033
Title: Exploring the Stellar Graveyard of the Milky Way

Abstract: 98% of all stars will end their lives as white dwarfs. In old stellar populations, such as globular clusters and stellar halos, the bulk of the progenitor stellar mass function above the present day turnoff is therefore now populated on the white dwarf cooling sequence. These remnants have remarkable properties and can be studied in exquisite detail to reveal their temperatures, gravities, and masses. In this talk, I will describe unprecedented HST imaging and Keck spectroscopic observations of these stars in old stellar populations. This work has led to the first global constraints on the mapping between initial stellar mass and final mass, and therefore has broad applications for understanding stellar evolution theory, mass loss, and chemical enrichment of the interstellar medium. Additionally, through a new technique, I will describe how we can invert the process of stellar evolution to establish a relation between the remnant mass in an old stellar population and the parent age. By applying this technique to nearby Milky Way halo stars, we measure the age of the inner halo of the Milky Way to be 11.4 ± 0.7 Gyr.

Daniela Calzetti (UMass)

Sept. 12, 2013, 3:45 p.m. — LGRT 1033
Title: KINGFISH, or Key Insights on Nearby Galaxies: a Far-Infrared Su

Abstract: By targeting the far-infrared and sub-millimeter regime with unprecedented sensitivity and angular resolution, the Herschel Space Telescope has provided new insights into both the phenomenology and the physics of dust emission from galaxies. I review the results obtained so far by KINGFISH (Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel), an Herschel Open Time Key Project, and by similar projects on galaxies within the local ~30 Mpc, where Herchel affords a spatial resolution better than ~ 0.8-5 kpc, and can thus probe the variety of environments within galaxies.

William Irvine (UMass)

May 2, 2013, 3 p.m. — LGRT 1033
Title: The Development of Astronomy & Astrobiology in the Five College

Abstract: The last 180 years of astronomy at the institutions now known as the Five Colleges include: students arriving at college by stage coach; an observatory built as an octagon; a famous poet; an infamous, illicit love affair; pioneering observations from the Chilean desert; early astrobiology; the first SETI, more than 100 years ago; the first astronomical observations from an artificial platform above the earth’s surface; an innovative way to augment department budgets; discrimination against women in astronomy; the Layzer-Irvine equation; the Hapke-Irvine Law; a 100-ft long absorption cell for infrared spectroscopy; telescopes built with telephone poles and chicken wire; a Nobel prize; the Rydbeck factor; the Five College Radio Astronomy Observatory; new interstellar molecules; viruses from space and a new physical/biological measurement unit; a phony press release picked up by the media; giving the International Halley Watch FITS; and, after 800 years, a Scottish coat-of-arms with a comet (Halley’s, of course).

Caution: some material suitable for mature audiences only.

There will be light refreshments available at 2:45 PM, prior to Professor Irvine's talk.

John O'Meara (Saint Michael's College)

April 25, 2013, 3:45 p.m. — LGRT 1033
Title: Rediscovering the Universe at Redshift 3

Abstract: The 1990's saw revolution of our understanding of the high redshift universe through the advent of 10 meter class telescopes and the application of large scale computer simulations to cosmology. Since that time, new advances in instrumentation and simulation have pushed the techniques from high redshift to more recent epochs. In this talk, I will discuss how we have returned to the universe at z~3 with new technologies, theories, and techniques, and how these advances can re-revolutionize our understanding of the universe over all cosmic times.

Debra Elmegreen (Vassar College)

April 11, 2013, 3:45 p.m. — LGRT 1033
Title: Local Analogs of Early Universe Galaxies

Abstract: The Hubble Ultra Deep Field in the redshift range z=1 to 5 is dominated by clumpy galaxies, whose kiloparsec-scale star-forming complexes have masses 100x greater than similar complexes in local spirals. The clumps evidently form from gravitational instabilities following gas accretion, and the galaxies transform into the familiar disk morphologies of nearby spirals after a Gyr. Though rare, there
are UV-bright local analogs of these distant clumpy galaxies that appear to be at an early evolutionary stage. I will compare star formation properties of local and distant galaxies based on photometry and spectroscopy, and present recent observations of local tadpole galaxies that show evidence for accretion of metal-poor gas.

Jeff Bary (Colgate )

March 28, 2013, 3:45 p.m. — LGRT 1033
Title: The Importance of Being Duplicitous: Why Binarity Matters

Abstract: In spite of the depiction of Luke Skywalker's home planet of Tatooine as orbiting two suns, astronomers have long assumed that such systems would be difficult if not impossible to form and remain stable. Recently, the Kepler space telescope has discovered several exoplanetary systems (Kepler 16-b, 34-b, 35-b, 47-b, and 47-c) in which the planet(s) orbit(s) both of the host stars. These recent detections highlight the importance of binary and higher order multiple systems to our overall understanding of the processes that lead to the formation of planets. In this talk, recent observational studies comprised of multi-epoch spectroscopic monitoring and high-spatial resolution spectral imaging of two distinctly different young binary systems will be presented. With both observational programs we seek to reveal the underlying dynamical complexity of such systems and the interactions between the stellar cores, the circumstellar disks, and circumbinary disk.

Helen Kirk (McMaster University)

March 14, 2013, 3:45 p.m. — LGRT 1033
Title: Filamentary Flows and Clustered Star Formation

Abstract: Most stars, including our Sun, are thought to have formed within a stellar cluster, yet much of the star formation process within this type of environment is poorly constrained. Recent results from the Herschel Space Telescope hint that dense filaments of gas and dust are intimately linked with star formation, for both isolated stars and clustered systems. Several models also predict the importance of filaments in cluster formation, but observations of the key predicted processes are limited. I will present results from a Mopra survey of the Serpens South system which addresses this lack of observations. Serpens South is a recently discovered young cluster forming deeply embedded within a prominent dense filament. As such, it provides an ideal testbed for the scenario of significant mass accretion onto clusters via filaments. I will finish by discussing ways in which numerical simulations of star formation can be used to gain a deeper understanding of the processes involved, highlighting ongoing efforts of the group at McMaster University.

B-G Anderson (SOFIA)

March 7, 2013, 3:45 p.m. — LGRT 1033
Title: Status of the Stratospheric Observatory for Infrared Astronomy (

Abstract: The Stratospheric Observatory for Infrared Astronomy (SOFIA) is now performing scientific observations and the Call for Proposals for the second open observing cycle is about to be released (late April). With an available wavelength coverage from the visual to sub-mm wavelengths and a long life time - including planned instrument upgrades, SOFIA will provide critical resource for the astronomical community for the next decade and beyond. Current and expected SOFIA instruments provide heterodyne spectroscopy in the THz band, including the line of [O I], [C II] and [N II] as well as OH, HD and many other hydrides, at high spectral resolution. Echelle spectroscopy in the Mid-infrared (MIR) which will allow observations of e.g. fine-structure lines of and H2 pure rotational lines. These will help address questions of interstellar chemistry and physics in star forming regions, PDRs and galaxies. Mid-infrared (MIR) grism spectroscopy, of e.g. dust and ices, can be used to address questions of the freeze-out of molecules from the gas phase to better understand the formation, destruction and characteristics of interstellar ices. Imaging in the MIR and FIR and FIR polarimetry can provide a more complete picture of the temperature, density and magnetic field structure of e.g. star forming cores. I will highlight the current and expected capabilities of SOFIA and some of the early science results achieved.

Robert Feldman (University of California, Berkeley)

Feb. 28, 2013, 3:45 p.m. — LGRT 1033
Title: It's the law - The role of star formation laws for galaxy evolut

Abstract: Empirical relations connecting star formation and the interstellar medium form the basis of many theoretical models of galaxy evolution. After reviewing the current observational status (and its limitations) of star formation laws, I will show what role they play for the evolution of various global galaxy properties. Observations of the mass-metallicity relation and of the cosmic star formation history, in particular, put stringent constraints on the actual functional relationship between star formation and the gas reservoir of galaxies. These results point towards a very simple and essentially time-independent star formation law that encapsulates most aspects of star formation relevant for the evolution of average galaxy properties across cosmic history.

Aaron Dutton (Max Planck Institute for Astronomy, Heidelberg)

Feb. 21, 2013, 3:45 p.m. — LGRT 1033
Title: Star Formation, Galaxy Formation and the Nature of Dark Matter

Abstract: The distribution of dark matter in galaxies provides a non-linear scale cosmological test of dark matter models. However, the utility of this test is at present limited by our lack of knowledge about how dark matter haloes respond to galaxy formation, and form of the stellar initial mass function. I will discuss recent progress in constraining these unknowns, including methods based on galaxy scaling relations and strong gravitational lensing. Finally, I will describe how the relation between stellar mass and galaxy rotation velocity (also known as the Tully-Fisher relation) together with the stellar mass function can be used to place constraints on the temperature of warm dark matter candidates.

Michael Boylan-Kolchin (University of California, Irvine)

Feb. 14, 2013, 3:45 p.m. — LGRT 1033
Title: Near-Field Cosmology: Big Science From Small Galaxies

Abstract: Dwarf galaxies are the most metal-poor and dark matter-dominated galactic systems known, and they therefore provide a unique window onto galaxy formation and the nature of dark matter. I will present predictions from N-body simulations based on the standard dark energy plus cold dark matter cosmological model for the abundance and structure of low-mass galaxies around the Local Group, highlighting potentially serious discrepancies between these predictions and observations. I will then discuss how baryonic processes or non-standard dark matter physics may modify this picture, and how the next generation of ground and space-based telescopes, coupled with more advanced numerical simulations, will vastly improve our knowledge. Finally, I will describe how studying the Local Group can guide our understanding of galaxy formation at cosmic dawn, and conversely, how observations of the high-redshift Universe can inform models of nearby galaxies.

Stella Offner (Yale)

Feb. 7, 2013, 3:45 p.m. — LGRT 1033
Title: Symbiotic Star Formation: Modeling the Complex Ecology of Molecu

Abstract: The details of star formation are intimately related to the natal molecular cloud environment. This environment is in turn shaped by radiative and kinematic feedback from embedded forming stars. In this talk, I will present gravito-radiation-hydrodynamic simulations of clustered star formation. I will explore how protostellar radiation and mass outflows impact the stellar initial mass function, multiplicity, and molecular cloud evolution. I will discuss the importance of producing "synthetic observations", for example by modeling dust and CO line emission, in order to connect numerical results directly to observables.

Smadar Naoz (CfA)

Feb. 5, 2013, 3:45 p.m. — LGRT 1033
Title: The Origin of Retrograde Hot Jupiters

Abstract: The search for extra-solar planets has led to the surprising discovery of many Jupiter-like planets in very close proximity to their host star, the so-called ``hot Jupiters'' (HJs). Even more surprising, many of these HJs have orbits that are eccentric or highly inclined with respect to the equator of the star, and some (about 25%) even orbiting counter to the spin direction of the star. This poses a unique challenge to all planet formation models. We show that secular interactions between Jupiter-like planet and another perturber in the system can easily produce retrograde HJ orbits. We show that in the frame of work of secular hierarchical triple system (the so-called Kozai mechanism) the inner orbit's angular momentum component parallel to the total angular momentum (i.e., the z-component of the inner orbit angular momentum) need not be constant. In fact, it can even change sign, leading to a retrograde orbit. A brief excursion to very high eccentricity during the chaotic evolution of the inner orbit allows planet- star tidal interactions to rapidly circularize that orbit, decoupling the planets and forming a retrograde hot Jupiter. We estimate the relative frequencies of retrograde orbits and counter to the stellar spin orbits using Monte Carlo simulations, and find that the they are consistent with the observations. The high observed incidence of planets orbiting counter to the stellar spin direction may suggest that three body secular interactions are an important part of their dynamical history.

Catherine Espaillat (CfA)

Jan. 31, 2013, 3:45 p.m. — LGRT RM 1033
Title: Characterizing Planet-Forming Disks Around Young Stars

Abstract: Theoretical simulations predict that a young planet will interact with the accretion disk surrounding its host star, clearing the material around itself and leaving behind an observational signature in the form of a clearing in the disk. Circumstellar disks with large, inner holes have been detected and are known as "transitional disks." A few years ago, Spitzer identified a new class of "pre-transitional disks" which have gaps rather than holes - they have an inner disk, a gap, and an outer disk. These gapped disks are the strongest evidence to date for disk clearing by planets and serve as signposts to guide young planet searches in the ALMA era.

More info.

Kristian Finlator (University of California Santa Barbara)

Jan. 29, 2013, 3:45 p.m. — LGRT 1033
Title: Galaxy Formation and Feedback During the Cosmic Dark Ages

Abstract: The study of structure formation during the first billion years is advancing rapidly, driven by pathfinding discoveries with the Hubble Space Telescope and motivated by anticipated studies that will wield next-generation facilities including ALMA, JWST, and LOFAR. I will show how detailed comparisons between numerical simulations and observations such as these inform our understanding of galaxy growth well into the cosmic dark ages. I will discuss observational and theoretical arguments that constrain how young galaxies ionized and heated the intergalactic medium. I will describe how the intergalactic medium's structure regulated the progress of cosmological reionization. Finally, I will show how a new class of cosmological radiation hydrodynamic simulations can be used to interpret existing observations of low-ionization metal absorbers that trace the earliest stages of structure formation.

Viviana Acquaviva (New York City College of Technology)

Jan. 24, 2013, 3:45 p.m. — LGRT 1033
Title: From galaxies to cosmic acceleration

Abstract: The accelerated expansion of the Universe could be due either to Dark Energy filling space, or to General Relativity failing on large scales. By studying the evolution and clustering of galaxies, we can probe both the expansion history and the linear growth of structure, thereby testing these two scenarios across cosmic time. I will present my efforts at improving our understanding of galaxy properties through Spectral Energy Distribution (SED) fitting, the process of comparing theoretical templates to observations in order to find which models best resemble the data. I will introduce GalMC, our publicly available Markov Chain Monte Carlo algorithm for SED fitting, and show how it can be used to recover the age, mass, dust content, metallicity and star formation history of galaxies, with reduced systematics. I will also present SpeedyMC, the fast kin of GalMC optimized for very large surveys, and describe our ongoing work as a joint analysis of photometric redshifts and SED fitting parameters. Finally, I will describe the science goals of the Hobby Eberly Telescope Dark Energy eXperiment (HETDEX), which will discover about a million Lyman Alpha Emitting galaxies at 2 < z < 3.5 and use them to shed light on the behavior of dark energy and gravity in this largely unexplored redshift range.

Aaron Evans (NRAO)

April 26, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: GOALS: The Great Observatories All-sky LIRG Survey

Abstract: Abstract: Luminous Infrared Galaxies (LIRGs) are observed primarily to be interacting and merging galaxies. They are the sites of rampant star formation and active galactic nuclei (AGN), which are fed by abundant supplies of molecular gas. However, the very property that led to their initial discovery as a significant population - their high infrared luminosity - also makes them difficult to study; the majority of the UV and optical light from young, massive stars and AGN is absorbed by obscuring dust and re-emitted in the infrared. The Great Observatories All-sky LIRGs Survey thus makes use of the diversity in wavelength coverage of the present space-based telescopes to probe the activity in a large (~ 100 - 200), flux-limited sample of LIRGs from the Revised Bright Galaxy Sample (RBGS). The majority of the talk will be devoted to discussing the survey as a whole. The latter part of the talk will be focussed specifically on a GOALS analysis of NGC 2623.

Stella Offner (CfA)

April 12, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Role of Episodic Accretion in Star Formation

Abstract: A number of young stars, like FU Orionis, have been observed to experience short abrupt changes in their luminosity of an order of magnitude or more. These changes are commonly attributed to episodic fluctuations in the accretion rate onto the star. However, the characteristics, frequency and importance of these bursts in the star formation process are poorly constrained. Recently, episodic accretion has been proposed as the origin of the stellar age spread in low-mass stars inferred in young clusters. Episodic accretion has also been suggested as a solution for the protostellar "luminosity problem," wherein protostars are observed to be dimmer than predicted by star formation models. In this talk, I will give an overview of each of these issues and evaluate whether episodic accretion could provide a solution. I will also discuss some current and future observational programs that may help to constrain protostellar accretion histories.

Bruce Draine (Princeton)

April 5, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Infrared, Submm, and Microwave Emission from Interstellar Dust

Abstract: Interstellar dust radiates most powerfully in the far-infrared, typically peaking in the 100-200um region. However, the emission at longer wavelengths is often unexpectedly strong. This is particularly true at microwave frequencies (~cm wavelengths), where sensitive studies of the CMB revealed emission that was far stronger than expected. This "anomalous microwave emission" is almost certainly produced in part by dust grains (PAHs) spinning at tens of GHz, although other processes may also contribute. The emission at mm- and submm wavelengths has also been problematic. Some galaxies (e.g., the SMC) show much stronger emission near ~1 mm than expected from "normal" dust models. This is sometimes attributed to large masses of very cold dust, but more likely it is telling us about new emission processes. I will argue that much of the submm excess in the SMC may be magnetic dipole emission from iron nanoparticles. If true for the SMC, this may presumably apply to other low-metallicity galaxies as well.

Daniel Eisenstein (CfA)

March 29, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Dark Energy and Cosmic Sound

Abstract: I will discuss how the acoustic oscillations that propagate in the photon-baryon fluid during the first million years of the Universe provide a robust method for measuring the cosmological distance scale. The distance that the sound can travel can be computed to high precision and creates a signature in the late-time clustering of matter that serves as a standard ruler. Galaxy clustering results from the Sloan Digital Sky Survey reveal this feature, giving a geometric distance to a redshift of 0.35 and an accurate measurement of Omega_matter. I will review our recent work on the theory and practice of the acoustic oscillation method and our latest cosmology results from SDSS-II. I will then present SDSS-III, which will use the acoustic method to produce 1% distance measurements in order to map the curvature and expansion history of the Universe and measure the evolution of dark energy.

Alexey Vikhlinin (CfA)

March 15, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: On the long-term future of X-ray astronomy

Abstract: Chandra has revolutionized X-ray astronomy by being a versatile observatory for studying objects ranging in scale from the inner structure of the Crab pulsar nebula to high-redshift AGNs, clusters of galaxies, and cosmology. Chandra is operating well and is expected to last into 2020's. In the next few years, we expect a launch of an array of smaller missions, which will open new areas of X-ray astronomy such as polarimetry, imaging at E>10 keV, sensitive surveys, high-resolution X-ray spectroscopy, ensuring a continues short-term vibrancy of the field. However, in the post-Chandra era, X-ray astronomy cannot be sustained by small-scale experiments, and there are no concrete plans for a powerful, observatory-class mission. What an X-ray observatory for the 2020's can look like? We are developing a concept, SMART-X, for a next-generation X-ray observatory with large-area, 0.5" resolution grazing incidence adjustable X-ray mirrors, high-throuput critical transmission gratings, and X-ray microcalorimeter and CMOS-based imager in the focal plane. High angular resolution is enabled by new technology based on controlling the shape of mirror segments using thin film piezo actuators deposited on the back surface. Science application include observations of growth of supermassive black holes sinse redshifts of ~10, ultra-deep surveys overs 10's of square degrees, galaxy assembly at z=2-3, as well as new opportunities in the high-resolution X-ray spectroscopy and time domain.

Caleb Scharf (Columbia)

March 8, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Outstanding questions for exoplanetary science

Abstract: Exoplanetary science has gone from non-existence to a burgeoning field in less than 20 years. I'll present an overview of where it stands now, from the extraordinary abundance of exoplanets to the remarkable diversity of system architectures and planetary characteristics. Many huge questions remain, and I'll discuss some work on planet formation and the nature of terrestrial-like worlds, including the application of new computer technology to planet discovery and system simulation.

David Hogg (NYU)

March 1, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Finding the dark matter

Abstract: One of the principal goals of Gaia and surveys like it is to infer the density map and formation history of the Milky Way. I present a few toy problems in which we use phase-space information for a snapshot of tracer particles to infer the matter density within the system. All known methods for performing this inference make multiple assumptions that are known to be false for the Galaxy, and few have made proper use of the observational noise model. I will express some optimism for methods that make use of cold phase-space structures and other kinds of rare but informative tracers.

Michael Kuhlen (UC Berkeley)

Feb. 28, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Computational Cosmology and Galaxy Formation

Abstract: Fueled by continuing advances in numerical methods and computational capabilities, the future of galaxy formation theory is going to be driven by numerical simulations. Yet computational galaxy formation is extremely challenging, owing to the multitude of important physical processes and the wide range of scales over which they operate. Much of the galaxy formation simulation work to date has relied on simple, and often ad-hoc, subgrid models for star formation and feedback. In this talk I will describe my recent efforts to improve this situation by including more realistic and physics-driven treatments of some of the relevant processes. As one example, I will discuss cosmological adaptive mesh refinement simulations in which star formation is regulated by the local abundance of molecular hydrogen. These simulations reproduce much of the observational phenomenology of star formation rates as a function of atomic and molecular gas content and metallicity. At the same time this new piece of physics leads to a suppression of the stellar content of low mass dark matter halos, thereby helping to explain the vexing dwarf galaxy problem.

Mark Krumholz (UC Santa Cruz)

Feb. 23, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Origin of the IMF

Abstract: Star-forming environments vary by orders of magnitude in density, pressure, metallicity, and other properties, yet the initial mass function (IMF) of the stars they produce remains stubbornly unchanged. Explaining the origin and universality of the IMF is one of the oldest problems in theoretical astrophysics, but in the last few years theoretical advances in understanding how gas fragments, together with algorithmic advances that have allowed simulations to include improved physics such as radiative transfer, have produced significant progress. I describe these advances, and lay out the beginnings of a theoretical model capable of explaining the IMF. This model suggests that the IMF is nearly but not perfectly universal, and the subtle variations that it admits provide avenues for future observational tests.

Daniel Wang (UMass, Amherst)

Feb. 21, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Stellar Feedback and Galaxy Evolution

Alyson Brooks (U. Wisconsin - Madison)

Feb. 16, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Toward the Formation of Realistic Galaxies

Abstract: Much progress has been made in recent years in forming realistic disk galaxies in fully cosmological simulations. Computational advances have allowed for unprecedented resolution, which in turn allows for a more realistic treatment of star formation and energy feedback. These improvements have led to a new examination of gas accretion, consumption, and loss in the formation of galaxy disks. I will show that a more realistic treatment of gas in simulated disk galaxies leads to a better match with observational results as a function of redshift. I will demonstrate that because star formation (i.e., gas consumption) varies with galaxy mass, the structure of dark matter within galaxies varies with mass. This leads to observable scaling relations as a function of galaxy mass, and resolves a number of long standing challenges within the CDM model. Realistic simulated galaxies are the necessary starting point for interpreting observations in light of galaxy formation theory.

Romeel Dave (U. Arizona)

Feb. 9, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Baryon Cycling: A Modern View of Galaxy Evolution

Abstract: Traditionally, galaxy formation theory has been based on connecting observable baryons to dark matter halos and their merger history. But in the past decade, hydrodynamic simulations of galaxy formation have elucidated a somewhat different view, in which galaxy growth is governed by an evolving balance between continual inflow from the intergalactic medium and strong, ubiquitous outflows. In this talk I will discuss the formalism of baryon cycling and the simulations that led to it, and highlight some of the new insights and interpretations that it yields for the stellar, gas, and metal content of galaxies. Of central importance in baryon cycling is the role of circum-galactic gas in regulating galaxy growth, and I will present results from simulations detailing this connection and its observational implications. I will argue that in the coming years, the holistic study of galaxies and their surrounding gas will be the key to understanding galaxy evolution across cosmic time.

Andrew Benson (Caltech)

Feb. 2, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Galaxy Formation Theory: The Next Decade

Abstract: I will present my view of how the field of galaxy formation theory should, and must, progress over the next decade to keep pace with expected observational advances. I will describe my current work aimed at establishing robust modelling techniques that can generate detailed realizations of astronomical datasets, and will discuss the challenges that must be met to reach the primary goal of my research program: inferring the underlying physical mechanisms of galaxy formation from observational measures.

Lars Hernquist (CfA)

Jan. 26, 2012, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Cosmology on a Moving Mesh

Abstract: Understanding the formation and evolution of galaxies in a cosmological context using numerical simulations remains an elusive goal. In this talk, I describe a new approach to modeling the hydrodynamics of galaxy formation in which the equations of motion are solved on a moving mesh. The use of a moving mesh makes the scheme fully Lagrangian, unlike popular particle-based codes which are quasi-Lagrangian in nature, and mitigates against advection errors when a spatially fixed grid is used. I present results from an initial study comparing results for a moving mesh with those obtained using a smoothed particle hydrodynamics solver. This preliminary work suggests that the new approach offers promise for resolving the long-standing problems which have plagued this field for nearly two decades.

Els Peeters (University of Western Ontario)

Dec. 8, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: PAH emission features as astrophysical probes

Jiangtao Li (UMass)

Dec. 1, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: CHANDRA SURVEY OF GALACTIC CORONAE AROUND NEARBY EDGE-ON DISK GA

Abstract: CHANDRA SURVEY OF GALACTIC CORONAE AROUND NEARBY EDGE-ON DISK GALAXIES

Pete Schloerb (UMass)

Nov. 17, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: LMT

Caleb Fassett (Mt. Holyoke)

Nov. 10, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Sugata Kaviraj (Imperial College London)

Nov. 3, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Early-type galaxies: the last 8 billion years

Jen Andrews (UMass)

Oct. 27, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Formation of Dust in Core Collapse Supernovae

Lynn Mathews (MIT Haystack Observatory)

Oct. 20, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Tails of Stellar Mass Loss: The HI 21-cm Line as a Probe of the

Abstract: Tails of Stellar Mass Loss: The HI 21-cm Line as a Probe of the Late Stages of Stellar Evolution

Desika Narayanan (University of Arizona)

Oct. 13, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Efficiency of Star Formation in High Redshift Galaxies

Kristen Coppin (McGill University)

Oct. 6, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Probing the Evolutionary Sequence of the Formation of Massive Ga

Abstract: Probing the Evolutionary Sequence of the Formation of Massive Galaxies

Jim Geach (McGill University)

Sept. 29, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Evolution of the Molecular Gas Fraction of Star-Forming Gala

Abstract: The Evolution of the Molecular Gas Fraction of Star-Forming Galaxies

Ben Oppenheimer (Leiden Observatory)

Sept. 22, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: A Full Confrontation of the Low-Redshift Galaxy-Intergalactic Me

Abstract: A Full Confrontation of the Low-Redshift Galaxy-Intergalactic Medium Relationship

Ed Jenkins (Princeton University)

Sept. 15, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Distribution of Thermal Pressures in the Diffuse Interstella

Abstract: The Distribution of Thermal Pressures in the Diffuse Interstellar Medium of our Galaxy

Tereasa Brainerd (Boston University)

Sept. 8, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Clues to the Orientations of Bright Galaxies inside their Dark M

Abstract: Clues to the Orientations of Bright Galaxies inside their Dark Matter Halos

Adam Frank (Rochester)

April 28, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Turbulence and Feedback in Star Forming Clouds: Who Stirs the Po

Abstract: Turbulence and Feedback in Star Forming Clouds: Who Stirs the Pot?

Kevin Covey (Cornell)

April 21, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Stars that go bump in the night; from Myrs to Gyrs

Alexandra Pope (U Mass)

April 14, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The cosmic history of dust-obscured star formation

Mary Putman (Columbia)

April 7, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Galaxy Gas Flows

Danilo Marchesini (Tufts)

March 31, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Massive Galaxies at 2<z<4: New Insights into Galaxy Formation an

Abstract: Massive Galaxies at 2<z<4: New Insights into Galaxy Formation and Evolution

Scott Ransom (NRAO)

March 24, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Detecting Gravitational Waves (and doing other cool physics) wi

Abstract: Detecting Gravitational Waves (and doing other cool physics) with Millisecond Pulsars

Jennifer Lotz (STScI)

March 10, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Galaxy Mergers through Cosmic Time

Joseph Meiring (UMass)

March 3, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Shadows of Galaxies: Quasar Absorption Line Observations of Gala

Abstract: Shadows of Galaxies: Quasar Absorption Line Observations of Galaxy Evolution

Jacqueline Van Gorkom (Columbia)

Feb. 24, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: From voids to clusters: HI imaging surveys of galaxies in differ

Abstract: From voids to clusters: HI imaging surveys of galaxies in different environments

Mark Brodwin (CfA)

Feb. 17, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The IRAC Shallow Cluster Survey (ISCS): Evolution of Galaxy Clus

Abstract: The IRAC Shallow Cluster Survey (ISCS): Evolution of Galaxy Clusters Over the Last 10 Gyr

Joe Adams (Cornell University )

Feb. 10, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: FORCAST: A First Light Facility Instrument for SOFIA

Adam Leroy (NRAO)

Feb. 3, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The HERACLES and THINGS View of Gas and Star Formation in Nearby

Abstract: The HERACLES and THINGS View of Gas and Star Formation in Nearby Galaxies

Lisa Kaltenegger (Harvard/MPIA )

Jan. 27, 2011, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Super-Earth & Life: a fascinating puzzle

Rachel Sommerville (STScI)

Dec. 9, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Kevin Schawinski (Yale )

Dec. 2, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Giovanni Fazio (CfA )

Nov. 18, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Fulvio Melia (University of Arizona and Amherst College)

Nov. 4, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Martin Elvis (CfA )

Oct. 28, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Anil Seth (CfA )

Oct. 21, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Nuclear Star Clusters and Black Holes

Mary Putman (Columbia )

Oct. 14, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Hector Arce (Yale )

Oct. 7, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Elena D'Onghia (CfA )

Sept. 30, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Resonant Stripping as the origin of dwarf spheroidal galaxies

Ute Lisenfeld (University of Granada, Spain and Caltech/IPAC )

Sept. 23, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Molecular gas and star formation in galaxy interactions

Bruce Elmegreen (IBM )

Sept. 16, 2010, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Star Formation and Galaxy Assembly at Redshifts 1-5

Pepi Fabbiano (CfA/Harward)

May 7, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: High-resolution X-ray observations of galaxies

Kelsey Johnson (University of Virginia)

April 30, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Star Formation & Galaxy Evolution in Compact Groups

Professor Dave Sanders ( )

April 23, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Origin and Evolution of Luminous Infrared Galaxies: new resu

Abstract: The Origin and Evolution of Luminous Infrared Galaxies: new results from the Spitzer-COSMOS survey

Laura Greggio (Padova Observatory (Italy))

April 21, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Progenitors Of Type Ia Supernovae

Ravi Sheth (University of Pennsylvania)

April 16, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: A little knowledge is a dangerous thing: Galaxy formation and ph

Abstract: A little knowledge is a dangerous thing: Galaxy formation and photometric redshift surveys

Dr. Bill Forman (Harvard/CfA)

April 9, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Shocks, Bubbles, and Filaments: the Interaction of Supermassive

Abstract: Shocks, Bubbles, and Filaments: the Interaction of Supermassive Black Holes with Gaseous Environments in Elliptical Galaxies, Groups, and Clusters

Kathryne Johnston (Columbia University)

April 2, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Local Group Manifesto

Nick Scoville (Caltech)

March 26, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Large Scale Structures and Galaxy Evolution in the COSMOS Survey

Paolo Cassata (UMass)

March 12, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Early-type galaxies: observational results and constraints on mo

Abstract: Early-type galaxies: observational results and constraints on models of galaxy formation

Dr. Tom Brown (the Space Telescope Science Institute)

March 5, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Star Formation Histories in the Andromeda Galaxy

Carol Lonsdale (National Radio Astronomical Observatories (NRAO), Charlottesvill)

Feb. 26, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: High redshift ULIRGs and obscured QSOs with Spitzer and WISE, an

Abstract: National Radio Astronomical Observatories (NRAO), Charlottesville, VA

High redshift ULIRGs and obscured QSOs with Spitzer and WISE, and future studies with Herschel, ALMA, EVLA, LMT and JWST

Robert Gutermuth (Smith College)

Feb. 19, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Spitzer Surveys of Nearby Regions of Star Formation: Census and

Abstract: Spitzer Surveys of Nearby Regions of Star Formation: Census and Structure

Professor Colin Norman (Hopkins University/STScI)

Feb. 12, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Star Formation in the Multi-phase ISM for Normal, Starbursting a

Abstract: Star Formation in the Multi-phase ISM for Normal, Starbursting and "Active Galaxies"

David Bowen (Princeton University)

Feb. 5, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Baryons Around Quasars and Galaxies

David Latham (CfA/Harvard)

Jan. 29, 2009, 3:45 p.m. — LGRT 1033 Lecture Area
Title: SUPER EARTHS and LIFE

Tim Heckman (Johns Hopkins University )

Dec. 11, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Jay Gallagher (University of Winsconsin Madison)

Dec. 4, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Blowin' in the Winds: Gas Outflows from Starbursting Galaxies

Desika Narayanan (CfA/Harvard)

Nov. 13, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Formation and Evolution of z~2 Submillimeter Galaxies

Priya Natarajan (Yale )

Nov. 6, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Mapping dark matter and dark energy using gravitational lensing

Abstract: Mapping dark matter and dark energy using gravitational lensing

Harry Ferguson (STScI)

Oct. 23, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Sukanya Chakrabarti (Harvard University)

Oct. 16, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Simulating & Observing Galaxy Evolution -- From Spirals to ULIRG

Abstract: Simulating & Observing Galaxy Evolution -- From Spirals to ULIRGs

Mariangela Bernardi ( University of Pennsylvania Philadelphia )

Oct. 9, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Dawn Erb (CfA/Harvard)

Oct. 6, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Mass, Kinematics, Metallicity and Gas Flows in High Redshift Gal

Abstract: Mass, Kinematics, Metallicity and Gas Flows in High Redshift Galaxies

Romeel Dave ( University of Arizona )

Sept. 25, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Lucio Mayer (ETH Zurich, Switzerland )

Sept. 22, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Piero Madau (University of California Santa Cruz )

Sept. 18, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Alexandra Pope (NOAO Tucson )

Sept. 8, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Christopher Conselice (University of Nottingham, UK )

Sept. 4, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Meg Urry (Yale)

May 1, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Cosmic Accretion and the Growth of Supermassive Black Holes

Kartik Sheth (Spitzer Science Center)

April 24, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Redshift Evolution of Galactic Structures (Bars, Bulges & Di

Abstract: The Redshift Evolution of Galactic Structures (Bars, Bulges & Disks) at z < 1 from COSMOS: Quantifying the Assembly of the Hubble Sequence

Mark Dickinson (NOAO)

April 15, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Histories of star formation and stellar mass assembly at high re

Abstract: Histories of star formation and stellar mass assembly at high redshift

Letizia Stanghellini (NOAO)

April 10, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Population of Magellanic Cloud Planetary Nebulae

Rosemary Wyse (Johns Hopkins)

April 3, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Dark Matter and Baryons in Dwarf Spheroidal Galaxies

Kyoung-Soo Lee (Yale)

March 27, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Understanding the Nature of Star Formation at High Redshifts wit

Abstract: Understanding the Nature of Star Formation at High Redshifts with Clustering

Antonella Nota (STScI)

March 13, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Star Formation in the Small Magellanic Cloud : does the environm

Abstract: Star Formation in the Small Magellanic Cloud : does the environment matter?

Marina Romanova (Cornell)

Feb. 28, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Accretion and Outflows in Young Solar-type Stars

Daniel Wang (UMass, Amherst)

Feb. 21, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Stellar Feedback and Galaxy Evolution

Jason Tumlinson (Yale)

Feb. 14, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: New Windows on the Epoch of First Light

Linda Tacconi (Max-Planck-Institut fur Extraterrestrische Physik, Germany)

Feb. 7, 2008, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Spatially Resolved Dynamics at z~2-3: New Insights into Galaxy F

Abstract: Spatially Resolved Dynamics at z~2-3: New Insights into Galaxy Formation and Evolution

Eric Wilcots (University of Wisconsin)

Dec. 6, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Probing the Baryon Content of Galaxy Groups: A Radio Perspective

Suzan Edwards (Smith College)

Nov. 29, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Protoplanetary Disks: The Accretion/Outflow Connection

Neill Reid (Space Telescope Science Institute)

Nov. 15, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Finding Earths: Ages & Metallicities of Exoplanet Hosts

Marla Geha (Yale)

Nov. 8, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Meet the New Neighbors: Kinematics of the Ultra-Faint Milky Way

Abstract: Meet the New Neighbors: Kinematics of the Ultra-Faint Milky Way Dwarf Galaxies

Neal Erickson (University of Massachusetts, Amherst)

Nov. 1, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Redshift Measurements of High-Z Submillimeter Galaxies

Kristine Spekkens (NRAO/Rutgers University)

Oct. 25, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Precision Cosmology and the Structure of Nearby Galaxies

Alice Shapley (Princeton University)

Oct. 18, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Metallicities and Physical Conditions in Star-forming Galaxi

Abstract: The Metallicities and Physical Conditions in Star-forming Galaxies at High-Redshift

Greg Rudnick (National Optical Astronomy Observatory)

Oct. 11, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Galaxies in Normal Intermediate Redshift Clusters

Sara Seager (MIT)

Oct. 4, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Exoplanets: Interiors, Atmospheres, and the Search for Habitable

Abstract: Exoplanets: Interiors, Atmospheres, and the Search for Habitable Worlds

Carol Christian (Space Telescope Science Institute)

Sept. 27, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Visualization of the Cosmos: Hubble Space Telescope and Sky in G

Abstract: Visualization of the Cosmos: Hubble Space Telescope and Sky in Google Earth

Christy Tremonti (University of Arizona)

Sept. 20, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Fossil Galactic Winds in Post-Merger, Post-Starburst Galaxies: E

Abstract: Fossil Galactic Winds in Post-Merger, Post-Starburst Galaxies: Empirical Evidence for Quasar-mode Feedback?

Hugh Crowl (Five College Astronomy Department)

Sept. 13, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Galaxy Transformation in the Virgo Cluster

Paul Goldsmith (JPL)

May 3, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Herschel Space Observatory: Potential, Plans, and Current St

Abstract: The Herschel Space Observatory: Potential, Plans, and Current Status

Todd Tripp (UMass)

April 26, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: A High-Resolution Survey of Low-Redshift QSO Absorption Lines: N

Abstract: A High-Resolution Survey of Low-Redshift QSO Absorption Lines: New Results on O VI Absorbers, Warm-Hot Intergalactic Gas, and Feedback

Lucio Mayer (University of Zurich)

April 19, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The role of the environment in shaping the nature and abundance

Abstract: The role of the environment in shaping the nature and abundance of dwarf galaxy satellites

Dennis Zaritsky (University of Arizona)

April 10, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: A New Twist on Galaxy Scaling Relations

Ann Zabludoff (University of Arizona)

April 5, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Importance of Lens Environments

Youn-Wook Lee (Yonsei University)

March 29, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Globular clusters with multiple populations as remaining cores o

Abstract: Globular clusters with multiple populations as remaining cores of galaxy building block

Grant Wilson (UMass)

March 8, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Submm Galaxies at mm Wavelengths

Arif Babul (University of Victoria)

Feb. 22, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Towards a Holistic View of Heating and Cooling in Galaxy Cluster

Abstract: Towards a Holistic View of Heating and Cooling in Galaxy Clusters

Eric Bell (MPIA)

Feb. 15, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Turning galaxies off

Richard Mushotzky (Goddard)

Feb. 8, 2007, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The History of Active Galaxies

Eve Ostriker (University of Maryland)

Dec. 7, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Lars Hernquist (Harvard)

Nov. 30, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Merger-Driven Evolution of Galaxies, Quasars, and Starbursts

Bruce Draine (Princeton)

Nov. 16, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Models of Interstellar Dust: Optical Extinction and Infrared Emi

Abstract: Models of Interstellar Dust: Optical Extinction and Infrared Emission

Chien Yi Peng (STScI)

Nov. 9, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Coevolution of Supermassive Black Holes and Galaxies Since t

Abstract: The Coevolution of Supermassive Black Holes and Galaxies Since the First Billion Years, as Seen Through Gravitational Lensing

Aeree Chung (UMass)

Nov. 2, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: VIVA, The New VLA HI Imaging survey of Virgo galaxies in Atomic

Abstract: VIVA, The New VLA HI Imaging survey of Virgo galaxies in Atomic gas - The art telling the galaxy evolution in the cluster environment

Zoltan Haiman (Columbia)

Oct. 26, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Feedback Processes During Reionization

Lorenzo Sorbo (UMass Physics)

Oct. 19, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Dark Energy: a Particle Theorist's Perspective

Leo Blitz (UC Berkeley)

Oct. 12, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Star Formation and Neutral Gas in Normal Galaxies

Arielle Phillips (FCAD)

Sept. 28, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Chasing a WHIM: The Changing Picture of the IGM

Min Yun (UMass)

Sept. 21, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Gas and Galaxy Evolution in Hickson Compact Groups

Dick McCray (University of Colorado)

May 18, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: SN1987A: The Birth of a Supernova Remnant

Catrina Hamilton (Mt. Holyoke)

May 11, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Resolving an Accretion Flow: Halpha Line Profiles of the Eclipsi

Abstract: Resolving an Accretion Flow: Halpha Line Profiles of the Eclipsing Binary System KH 15D

Kathryn Johnston (Wesleyan)

May 4, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Stellar Halos and Satellite Systems in a LCDM Universe

John Salzer (Wesleyan)

April 20, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Properties of Galaxies Discovered in "Blind" H I Surveys -- ADBS

Abstract: Properties of Galaxies Discovered in "Blind" H I Surveys -- ADBS & ALFALFA Galaxies

Shantanu Basu (University of Western Ontario)

April 13, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: From Clouds to Cores to Protostars and Disks: New Insights from

Abstract: From Clouds to Cores to Protostars and Disks: New Insights from Numerical Simulations

Grant Wilson (UMass)

April 6, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: First Results from the AzTEC 1mm Camera

Rom Bania (Boston University)

March 30, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Constraining the Chemical Evolution of the Milky Way

Romeel Dave (University of Arizona)

March 28, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Impact of Galactic Outflows Across Cosmic Scales

Samir Salim (UCLA)

March 14, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Shedding UV Light on Galaxy Evolution

Jim Stone (Princeton)

March 9, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Numerical Models of Accretion Flows Around Black Holes

Kim-Vy Tran (Leiden Observatory)

March 8, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Origin of Early-Type Galaxies in Rich Clusters

Karl Gordon (University of Arizona)

March 6, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Spitzer Observations of the Aromatic Features in M101 H II Regio

Abstract: Spitzer Observations of the Aromatic Features in M101 H II Regions and Starbursts

Julio Navarro (University of Victoria)

March 2, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Galaxy Formation and the Formation of the Galaxy

Jeffrey Newman (UC Berkeley)

Feb. 28, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: From Fine Structure to Large-Scale Structure with the DEEP2 Gala

Abstract: From Fine Structure to Large-Scale Structure with the DEEP2 Galaxy Redshift Survey

Mauro Giavalisco (STScI)

Feb. 23, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: GOODS news on Galaxy Evolution

Daniela Calzetti (STScI)

Feb. 21, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Panchromatic View of Star Formation

Risa Wechsler (University of Chicago)

Feb. 14, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Lighting up the Dark: Connecting Galaxies to Mass

Malcolm Longair (Cavendish Lab, University of Cambridge)

Feb. 9, 2006, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Most Luminous Radio Galaxies

Somak Raychadhury (University of Birmingham)

Dec. 15, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Evolution of Galaxies in Groups

Erik Rosolowsky (Harvard CfA)

Dec. 8, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Giant Molecular Clouds Across Galactic Environments

Michael Stage (UMass Amherst)

Dec. 1, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Estimating the Rates of Electron Acceleration in Supernova Remna

Abstract: Estimating the Rates of Electron Acceleration in Supernova Remnant Shocks using Chandra

Pieter van Dokkum (Yale)

Nov. 17, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Recent Assembly of Elliptical Galaxies

Greg Bryan (Columbia)

Nov. 10, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The First Stars in the Universe

Mark Gurwell (Harvard CfA)

Nov. 3, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: When You're Hot, You're Hot, and When You're Not, You're Not: (S

Abstract: When You're Hot, You're Hot, and When You're Not, You're Not: (Sub)Millimeter Studies of Venus and the Pluto/Charon Binary

Elliott Horch (UMass Dartmouth)

Oct. 27, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: High Resolution Imaging of Binary Stars with HST and the WIYN Te

Abstract: High Resolution Imaging of Binary Stars with HST and the WIYN Telescope post-Hipparcos

Chuck Joseph (Rutgers)

Oct. 20, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Ultraviolet Instrumentation and the Proposed HAWK Long-Duration

Abstract: Ultraviolet Instrumentation and the Proposed HAWK Long-Duration Balloon Mission

Kenneth Sembach (STScI)

Oct. 13, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Low Redshift Intergalactic Medium - Current Observations and

Abstract: The Low Redshift Intergalactic Medium - Current Observations and Future Observational Prospects

David Schiminovich (Columbia)

Oct. 6, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Star Formation Histories Now and Then: Ultraviolet Insights from

Abstract: Star Formation Histories Now and Then: Ultraviolet Insights from GALEX

Arlin Crotts (Columbia)

Sept. 29, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Halo Microlensing in M31

Stephanie Courteau (Queen's University)

Sept. 22, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Puzzles in the Structure of Spiral Galaxies

Andreea Font (Wesleyan)

Sept. 15, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Chemical Abundance Distributions of Galactic Halos and their Sat

Abstract: Chemical Abundance Distributions of Galactic Halos and their Satellite Systems in a LamdaCDM Universe

Eric Linder (Lawrence Berkeley Laboratory)

May 13, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Shedding Light on the Dark Universe

Jessica Rosenberg (CfA)

May 12, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Gas, Galaxies, and Star Formation: Low-z Constraints on Galaxy E

Abstract: Gas, Galaxies, and Star Formation: Low-z Constraints on Galaxy Evolution

Sarbani Basu (Yale)

May 5, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Some recent results in helio and asteroseismology

Douglas Whittet (Rensselaer Polytechnic Institute)

April 28, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Interstellar Dust and Astrobiology: Overview and Current Researc

Abstract: Interstellar Dust and Astrobiology: Overview and Current Research

Mark Fardal (UMass)

April 14, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Interpreting the Giant Stellar Stream in M31

Andrew Baker (NRAO Maryland)

April 7, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Millimeter Observations of High-Redshift Galaxies

Aracil Bastien (UMass)

March 31, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Multiple Line of Sight to Study the Absorber Systems

Yangsen Yao (UMass)

March 24, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Warm-hot Gas in and Around the Milky Way: X-ray Absorption Line

Abstract: Warm-hot Gas in and Around the Milky Way: X-ray Absorption Line Diagnostics

Mark Heyer (UMass)

March 10, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Gas dynamics in star-forming regions

Pete Schloerb (UMass)

March 3, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Large Millimeter Telescope

Arend Slius (UMass)

Feb. 24, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Galactic dynamics and planetary nebulae

Ari Maller (UMass)

Feb. 17, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: How the Galaxy got its Mass and Other Just So Stories

Dan McIntosh (UMass)

Feb. 10, 2005, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Evolution of Spheroid-dominated Galaxies Over the Last Half of C

Abstract: Evolution of Spheroid-dominated Galaxies Over the Last Half of Cosmic History

Ken Rines (Yale)

Dec. 19, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The Infall Regions of Galaxy Clusters

Abraham Loeb (Harvard)

Dec. 16, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Mapping Cosmic Hydrogen In the Infant Universe

Jiasheng Huang (CfA)

Dec. 2, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Spitzer IRAC GTO programs

Pepo Fabbiano (CfA)

Nov. 18, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: X-ray observations of galaxy mergers with Chandra

Barry McKernan (Maryland)

Nov. 4, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: The search for the hot missing matter

David Hogg (NYU)

Oct. 28, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Galaxy formation events at low redshift

Frank wan den Bosch (ETH, Zurich)

Oct. 26, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Lighting up the dark matter

Uros Seljak (Princeton)

Oct. 21, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title:

Xiaohu Yang (UMass)

Oct. 14, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Linking galaxies to dark matter halos

David Weinberg (Ohio State)

Oct. 7, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: What Can We Learn From Galaxy Clustering?

Bryan Penprase (Pomona College)

Sept. 28, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Nebular Diagnostics of HII regions in M83, NGC300, and the Anten

Abstract: Nebular Diagnostics of HII regions in M83, NGC300, and the Antenna Galaxies: Getting Spectral Information from Images

Brice Menard (IAS, Princeton)

Sept. 23, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Lensing by absorber systems

Mike Blanton (NYU)

Sept. 6, 2004, 3:45 p.m. — LGRT 1033 Lecture Area
Title: Extremely low luminosity galaxies in the field