Meeting Presentations [PDF]
Stefi Baum, RIT
Talk: Keeping the Embers Burning - Star Formation Amidst AGN Feedback in Clusters
June 11, 2013 (11:40 AM - 12:00 PM)
We present Hubble Space Telescope Far ultraviolet observations which reveal signatures of ongoing star formation amidst AGN feedback in central dominant galaxies in clusters. Implications for feedback models and growth of central dominant galaxies are discussed.
Eric Bell, University of Michigan
June 11, 2013 (9:30 AM - 10:00 AM)
Steven Boada, Texas A&M University
Poster: Galaxy Assembly at Redshift Two Through Internal Colors in CANDELS
June 10 - 12, 2013
We study the variation of internal colors within 1189 galaxies with redshifts between 1.5 < z < 3.5 using Hubble Space Telescope imaging from the CANDELS GOODS and UDF fields. We measure the Internal Color Dispersion (ICD), the variation in color about the mean, of galaxies to quantify the diversity of stellar populations and dust extinction. This metric is then compared with other galaxy properties, stellar masses, total colors, morphological indicators, color gradients, dust indicators, and redshifts. We find over this redshift range most galaxies (~75%) show low variation in internal colors. Of the galaxies with high ICD, the majority have masses between 3x10^9 - 6x10^10 Msol, disk morphologies based on Sersic fitting, and indications of significant dust extinction. We argue that most, perhaps all, galaxies with high ICD are undergoing spheroid formation, where the forming bulge is obscured by dust, and only becomes visible after dust dissipation. We discuss how observations of near-IR IFUs on 25m-class telescopes, such as GMTIFS on the Giant Magellan telescope will resolve the spatial kinematics and dust extinction (using Balmer decrements) of galaxies. Comparing the properties of such field-spectroscopic data to galaxy internal colors and morphologies will enable strong constraints on the physical properties to understand these possible transition phases in galaxies. This allows us to better determine which galaxies show color variation due to dust dissipation and bulge formation, due to interactions, or due to some yet-unknown process.
Rolando M. Branly, Broward College
Poster: Community Collaborations and Undergraduate Astronomy Research Projects
June 10 - 12, 2013
Hsiao-Wen Chen, University of Chicago
Invited Talk: Interstellar Medium in Distant Galaxies
June 11, 2013 (2:30 PM - 3:00 PM)
Ke-Jung Chen, University of Minnesota
Talk: Energetic Supernovae from the Cosmic Dawn
June 10, 2013 (5:10 PM - 5:30 PM)
We present the results from our 3D supernova simulations by using CASTRO, a new radiation-hydrodynamics code. The first generation of stars in the universe ended the cosmic dark age by shining the first light. But what was the fate of these stars? Based on the stellar evolution models, the fate of stars depends on their masses. Modern cosmological simulations suggest that the first stars could be very massive, with a typical mass scale over 50 solar masses. We look for the possible supernovae from the death of the first stars with initial masses over 50 solar masses. Besides the iron-core collapse supernovae, we find energetic thermonuclear supernovae, including two types of pair-instability supernovae and one type of general-relativity instability supernovae. Our models capture all explosive burning and follow the explosion until the shock breaks out from the stellar surface. We will discuss the energetics, nucleosynthesis, and possible observational signatures for these primordial supernovae that will be the prime targets for future large telescopes such as the GMT, JWST, LSST, and TMT.
Alan Dressler, Carnegie Observatories
Invited Talk: Studying galaxy evolution with GMT plus other powerful new facilities
June 10, 2013 (11:00 AM - 11:30 AM)
PDF, 17.58 MB
GMT, in combination with other powerful facilities such as JWST, WFIRST, ALMA, and SKA, will make fundamental contributions to our program of describing and understanding the birth and evolution of galaxies.
James S Dunlop, University of Edinburgh
Invited Talk: Observational Studies of First Light and Reionization
June 10, 2013 (4:00 PM - 4:30 PM)
I will review and discuss the latest observational studies of galaxies in the first billion years of cosmic time, and the resulting implications for our understanding of cosmic reionization. Key new results include studies of Lyman-break galaxies and the evolving galaxy UV luminosity function at z > 7 with HST (UDF12 + CANDELS), and observational constraints on the emergence of Lyman-alpha line emission from the young Universe. I will also discuss the prospects for further progress in this area with near-infrared spectrographs, HST, JWST, and future giant ground-based telescopes such as GMT.
Maxim Eingorn, North Carolina Central University
Talk: Gravitational potentials and dynamics of galaxies against the cosmological background
June 12, 2013 (9:30 AM - 9:50 AM)
PDF, 0.65 MB
The Universe is considered deep inside the cell of uniformity, where it is filled with inhomogeneously distributed galaxies perturbing the cosmological background (described, e.g., by standard models with conformally flat, spherical or hyperbolic spaces). It is shown that only in the last case there exists an explicit expression for the gravitational potential of an arbitrary number of randomly distributed inhomogeneities, finite at any point including spatial infinity. Bearing this result in mind, dynamics of Milky Way and Andromeda as well as surrounding dwarf galaxies forming the Hubble flow is investigated and illustrated in detail, taking into account both the gravitational attraction between them and the cosmological expansion of the Universe. It is demonstrated that there are always characteristic dimensions at which these two opponents become comparable. For our group of galaxies it happens theoretically at approximately 1 Mpc in agreement with the observations. Besides, the future collision between Milky Way and Andromeda is considered in the cosmological context in presence and absence of dynamical friction. The corresponding critical values of parameters of the problem are found.
Henry C. Ferguson, Space Telescope Science Institute
Invited Talk: An Empirical View of Galaxy Evolution
June 11, 2013 (9:00 AM - 9:30 AM)
Galaxy assembly is a complex process that is intimately linked to the behavior of dark matter, black holes, star-formation, and feedback. This talk will focus on recent progress and open questions that may challenge even JWST, LSST and 30-m class telescopes.
Steven Finkelstein, University of Texas at Austin
Talk: Spectroscopy in the Distant Universe
June 10, 2013 (4:50 PM - 5:10 PM)
We have recently performed some of the deepest near-infrared spectroscopy of the distant universe ever, using MOSFIRE on Keck. I will show the results of our study, and discuss the limitations of current instrumentation in the context of the next generation of large telescopes. I will discuss how current instrumentation is insufficient to confirm the redshifts to the vast majority of observed distant galaxies, let alone diagnose the ionization state of the IGM. I will highlight ways forward for the GMT, both with planned first-light instruments, and discuss ideas for second generation instrumentation which would open up this field.
Wendy L Freedman, Carnegie Observatories
Invited Talk: Welcome from GMTO
June 10, 2013 (8:40 AM - 8:55 AM)
Gabor Furesz, Smithsonian Astrophysical Observatory
Poster: G-CLEF: frist light instrument - first light science
June 10 - 12, 2013
The G-CLEF (GMT-Consortium Large Earth Finder) instrument is an optical echelle spectrograph that is currently scheduled to be available on the GMT as a first light facility. The conceptual design of G-CLEF has been developed to be a general-purpose echelle spectrograph with precision radial velocity capability. We have defined the performance envelope to address several of the highest science priorities in the Decadal Survey, and will exploit synergy with other top priority national astronomical facilities (LSST, JWST). The peak efficiency of the spectrograph is >35% and the passband is 3500-9500A. The baseline is a fiber feed with three observing modes: High Throughput, Precision Abundance and PRV. The respective resolving powers and sky coverage of these modes are R~ 25,000 (1.2''), 40,000 (0.7'') and 120,000 (0.7''). We also anticipate having a R~40,000 (0.7'') Multi-object Spectroscopy mode with a multiplex of ~40 fibers and an integrated field unit. Recent changes in the telescope design opened the possibility to a direct slit feed for improved blue throughput.
Jonathan P. Gardner, NASA's Goddard Space Flight Center
Invited Talk: Status of the James Webb Space Telescope Project
June 10, 2013 (11:30 AM - 12:00 PM)
PDF, 7.8 MB
The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes. It will be a large (6.6m) cold (50K) telescope launched into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. The science goals for JWST include the formation of the first stars and galaxies in the early universe; the chemical, morphological and dynamical buildup of galaxies and the formation of stars and planetary systems. Recently, the goals have expanded to include studies of dark energy, dark matter, active galactic nuclei, exoplanets and Solar System objects. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Near-Infrared Imager and Slitless Spectrograph will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. The observatory is confirmed for launch in 2018; the design is complete and it is in its construction phase. Recent progress includes the completion of the mirrors, the delivery of the first flight instruments and the start of the integration and test phase.
Marla Geha, Yale University
Invited Talk: Ultra-Faint Dwarf Galaxies
June 12, 2013 (11:00 AM - 11:30 AM)
Mike D Gladders, Chicago
Invited Talk: Cluster Lenses
June 12, 2013 (9:00 AM - 9:30 AM)
Jeong-Sun Hwang, Korea Institute for Advanced Study
Poster: Simulations of galaxy-galaxy interactions including hot and cold gas
June 10 - 12, 2013
Minjin Kim, Carnegie Observatories/KASI
Poster: AGN-driven outflow in Young Radio Quasars
June 10 - 12, 2013
We present near-infrared spectra of young radio quasars. The detected objects have typical redshifts of z~2 and [OIII] luminosities of 10^47 erg/s comparable to those of luminous quasars. Based on the intensity ratios of narrow emission lines, we find that these objects are likely to be powered by active galactic nuclei (AGNs). The [O III] line is exceptionally broad, with full width at half maximum ~ 1500 km/s, significantly larger than that of ordinary distant quasars. We argue that these large line widths can be explained by jet-induced outflows.
Young-Lo Kim, Yonsei University
Poster: The Evolution-Free and Dust-Free Dark Energy Test with Type Ia Supernovae in the GMT Era
June 10 - 12, 2013
The luminosity evolution of Type Ia supernova (SN Ia) and dust extinction play major roles in the systematic uncertainties in the SN cosmology. In order to overcome these obstacles, here we propose to use GMT-GMACS to take spectra for early-type host-galaxies of SNe Ia in the redshift range between 0.2 and 1.0. This high-redshift sample will be taken from Dark Energy Survey (DES), which expects more than 200 early-type hosts at this redshift range. They will be compared with nearby early-type hosts, for which we are now obtaining low-resolution spectra. We will select host-galaxies of same population age range for both nearby and high-redshift samples to reduce the possible evolution effect. Since we are dealing with early-type galaxies, our test is also less affected by dust extinction. We expect that our evolution-free and dust-free dark energy test will provide more robust results on the nature of dark energy.
Juna Kollmeier, Carnegie Observatories
Invited Talk: Gas, Galaxy formation, and the GMT
June 11, 2013 (2:00 PM - 2:30 PM)
Andreas J Korn, Department of Physics and Astronomy, Uppsala University, Sweden
Talk: Observing BBN: trouble in precision-cosmology paradise?
June 12, 2013 (11:50 AM - 12:10 PM)
I will review the current status of observational studies of the primordial (aka Big Bang Nucleosynthesis, BBN) abundances of D, He-4, Li-6 and Li-7, in light of the recent ESA-Planck constraints on Omega_baryon. Limiting factors of 8-10m-class studies will be discussed, and an outlook for GMT/ELT-type science will be given.
Andrey Kravtsov, University of Chicago
Talk: Size-virial relation of galaxies and its evolution
June 12, 2013 (9:50 AM - 10:10 AM)
I will describe the first estimate of relation between half-light radii of galaxies and virial radius of their halos. Unlike size-stellar mass relation, the size-virial radius relation is linear and scatter and amplitude of this relation is consistent with expectations of models in which size is set by specific angular momentum matter acquires during halo collapse. This implies that sizes of both disk and spheroidal galaxies are set by specific angular momentum. This result was not expected and needs to be understood. In particular, studies of evolution of galaxy sizes, which will be greatly facilitated by GMT, will be crucial to test this and alternative interpretations about galaxy sizes.
Richard G. Kron, University of Chicago
June 10, 2013 (8:55 AM - 9:00 AM)
Varsha P. Kulkarni, University of South Carolina
Talk: Metals and Stars in Quasar Absorber Galaxies
June 11, 2013 (4:40 PM - 5:00 PM)
Damped and sub-damped Lyman-alpha absorbers dominate the mass density of neutral gas in the universe. Furthermore, they enable reliable determinations of element abundances in distant galaxies. Recent studies have suggested a potential disparity between predictions of chemical evolution models and observations of metallicities of low-redshift DLAs. However, the corresponding information is not available for low-redshift sub-DLAs. We report HST COS measurements of element abundances in sub-DLAs at z < 0.6, and discuss implications for models. We also discuss results of our ongoing integral field spectroscopic survey of DLA/sub-DLAs. These observations enable us to map the distribution of star formation rates and emission-line metallicity in the absorber galaxies. Observations such as these for bigger samples with future extremely large telescope facilities will give powerful constraints on models of galaxy chemical evolution.
Benjamin L'Huillier, Korea Institute for Advanced Study
Poster: The rate and type of halo interactions
June 10 - 12, 2013
Interactions play a major role in shaping galaxies. Using comsological N-body simulations, we study the rate of halo interactions in different ranges of redshift, environment, and halo masses as a function of the mass ratio, distance to the neighbour, and impact parameter.
Timothy M. Lawlor, Penn State University - Brandywine
Poster: Evolution and Supernova Lightcurves for Early Universe Stars
June 10 - 12, 2013
We present evolution light curve calculations for Population III, Z = 0.0 stars for a range of masses from 15 - 40 solar masses.
Chris E Lidman, Australian Astronomical Observatory
Talk: Constraining dark energy with the rest-frame near-IR Type Ia supernovae Hubble diagram
June 12, 2013 (2:00 PM - 2:20 PM)
PDF, 0.73 MB
Constraining the properties of dark energy with observations of Type Ia supernovae in the rest-frame near-IR is a potentially exciting alternative to the current approach of constraining dark energy with observations in the rest-frame optical. In the rest frame H-band, for example, the dispersion in the inferred distance to these objects is an impressively small 5%, and there is potential to reduce this even further if better k-corrections can be derived. Observing distant supernova (i.e. supernovae up to z~0.7) in the rest-frame near-IR is probably beyond the reach of 8m class facilities, even with MCAO. However, with GMTIFS , such observations will be routine.
Ting Li, Texas A&M University
Poster: GMACS Exposure Time Calculator
June 10 - 12, 2013
GMACS has been selected as one of the first-light instruments for the Giant Magellan Telescope (GMT). We have designed a web-based Exposure Time Calculator (ETC) for GMACS based on the telescope parameters, the optical design of the instrument, the expected throughput of the optics, and the sensitivity of the detector. The GMACS ETC is able to calculate the Signal-to-Noise of different objects for various science cases, from individual stars in the Milky Way and nearby dwarf spheroidal galaxies, to the galaxies in the distance Universe. We present a few simulated GMACS spectra and show that GMACS will be a powerful instrument for spectroscopic follow-up of future large sky surveys, such as Dark Energy Survey and Large Synoptic Survey Telescope.
Daniel C Masters, University of California, Riverside / Carnegie Observatories
Poster: Near-IR Spectroscopy with Magellan FIRE of Starbursting Galaxies at 1.3 < z < 2.3 selected from the WFC3 Infrared Spectroscopic Parallels (WISP) Survey
June 10 - 12, 2013
We are obtaining high-resolution, near-IR spectra of emission-line galaxies at intermediate redshift with the FIRE echelle spectrometer on the Magellan Baade 6.5 meter telescope. The sample of galaxies at z~1.5 and z~2.2 were selected from the WISP survey on the basis of high equivalent-width emission lines (in particular [OIII] λ5007) detected in the HST/WFC3 grism spectra. The high sensitivity of the WFC3 grism spectra to emission line galaxies from z=0.5-2.5 provides an unbiased sample of strongly star-forming galaxies at the redshifts of interest, allowing us to investigate their properties down to low masses at the peak epoch of star formation. Here we present spectra and initial results of this ongoing project.
Patrick J McCarthy, GMTO
Invited Talk: Status of the Giant Magellan Telescope Project
June 10, 2013 (9:00 AM - 9:30 AM)
Jeffrey A Newman, University of Pittsburgh
Talk: Photometric Redshift Calibration with Extremely Large Telescopes
June 11, 2013 (5:00 PM - 5:20 PM)
PDF, 2.44 MB
One of the greatest areas of synergy between extremely large telescopes and future dark energy experiments will come via spectroscopy needed to tune photometric redshift algorithms; the same spectroscopy will simultaneously provide a wealth of information about galaxy evolution. In this talk, I will describe the anticipated needs and the characteristics of observing campaigns that could strengthen LSST studies of dark energy. The relatively wide field of view, broad wavelength coverage, and high degree of multiplexing anticipated for GMT multi-object spectroscopy would be particularly well suited for this work.
Nikhil Padmanabhan, Yale University
Invited Talk: The Next Generation Spectroscopy Surveys
June 10, 2013 (10:00 AM - 10:30 AM)
Casey Papovich, Texas A&M
Talk: The Assembly of Andromeda and Milky-Way-type galaxies, prospects for GMT
June 11, 2013 (10:00 AM - 10:20 AM)
Andromeda and the Milky Way are typical (''L*'') galaxies, and understanding their formation enables tests of galaxy evolution for the most common objects. I will describe the empirical evolution of these galaxies by tracking their progenitors out to z~3 using data from deep medium-band near-IR survey (zFourGE combined with CANDELS) combined with far-IR data from Spitzer and Herschel. Redshifts greater than about 1 correspond to the main star-formation stages in both galaxy progenitors, where the progenitors have properties consistent with the build up of stellar disks. At redshifts below 1, spheroids begin to develop in the galaxy progenitors, and these correspond to a transition from predominantly star-forming stages to stages of more quiescence. To understand how this transition stage star-formation activity and morphology are connected requires dynamical information for a large (statistically significant) sample of Andromeda and Milky-Way-type progenitors to determine if spheroid build-up results from mergers or more secular processes. I will discuss how such a survey will be easily achievable with instruments such as GMTIFS on the GMT.
Michael J Pierce, University of Wyoming
Talk: Quantifying the Assembly History of Galaxies with GMT
June 11, 2013 (10:40 AM - 11:00 AM)
PDF, 4.22 MB
The GMT offers the opportunity to quantify the assembly history of galaxies using the traditional scaling relations such as the fundamental plane (FP) of elliptical galaxies and the Tully-Fisher relation (TF) for spiral galaxies. A key project to characterize the FP over a range of redshifts ( z < 1.5) would enable us to quantify the relative role of wet vs. dry mergers in the assembly of elliptical galaxies. A corresponding key project to examine the TF and the distribution function of circular velocities would enable the characterization of disk formation, and the star formation history vs. potential well depth. These data will provide significant constraints on the next generation of models of galaxy assembly.
Marc Postman, Space Telescope Science Institute
Invited Talk: High Redshift Galaxies in CLASH
June 10, 2013 (3:00 PM - 3:30 PM)
PDF, 8.02 MB
The Cluster Lensing And Supernova survey with Hubble (CLASH) has revealed hundreds of strongly lensed galaxies at z > 6, including several z > 9 candidates. I will summarize the results and their implications for the early star formation history of the universe and for the identification of the population of objects responsible for the reionization of the universe.
Roberto Puddu, ''Sapienza'' University of Rome, University of Siena (Italy)
Poster: New Frontiers for Cosmology
June 10 - 12, 2013
In modern cosmology a major role is played by two rising factors: the study of galaxies distribution and clustering as an empirical check of structure formation models, and the CMB polarization in order to understand physics of primeval fireball. The former point can also yield: -constraints on the cosmological constant value by counting the galaxies density at different redshifts -primordial structure and Star Formation Rate at z=10 -combining X emission with SZ effect, both produced by galaxies clusters, it is possible to determine the Hubble constant value with great accuracy. The latter point is now standing out as the possible experimental proof for inflation: B-modes anisotropies in the CMB originate from tensor fluctuations produced during the inflationary phase: this step is crucial towards understanding the primordial Universe. However, the expected level of this signals is so small that their detection requires a new generation of instruments with high sensitivity and extremely good control of systematic effects. A critical step to safeguard the performance for the detection of such a small signal is the calibration of the bolometers. There have been tested new methods for this purpose, based on the optical properties of thin dielectric sheets. This is what is going to do the QUBIC experiment, ground-based telescope at Dome C, Antarctica. The innovation is brought by the new concept of bolometric interferometry, joining the advantage in sensitivity of bolometric detectors, to the one in systematic effects coming up from interferometry.
Ryan F. Quadri, Carnegie Observatories
Talk: The Buildup of the Red Sequence with Cosmic Time
June 11, 2013 (11:20 AM - 11:40 AM)
As galaxy surveys push to higher redshifts and to lower masses, we are obtaining an increasingly comprehensive view of how the red sequence builds up with time. I will present recent results regarding the identification of passive galaxies at z>3, the evolution in mass and structural properties, the growth due to mergers, and the role of environmental effects -- which are shown to be particularly important at the lowest masses.
Brett Salmon, Texas A&M University
Poster: High Redshift 3.5 < z < 6.5 Galaxy Evolution with CANDELS and GMT
June 10 - 12, 2013
We study the evolution in spectral-energy-distributions (SEDs) of high-redshift galaxies (3.5 < z < 6.5) using data from the CANDELS and UDF fields. Our custom SED fitting procedure incorporates the effects of nebular emission lines and various dust attenuation models, with updated Bruzual & Charlot (2003) stellar population synthesis models. When nebular emission lines are included and when using an SMC-like dust attenuation curve compared to a starburst attenuation curve (Calzetti et al. 2000), both the inferred stellar mass and SFRs are systematically lowered by 0.14 and 0.3-0.7 dex respectively. We follow objects at a constant comoving number density n(<M_UV)= 2x10^-4 Mpc^-3, and derive an average rising SFH across the redshift range. We evolve faint model galaxies according to our SFH and easily reproduce the bright end stellar mass-UV magnitude. A limitation in the study of galaxies in this redshift range is that we depend strongly on photometric redshifts, which may lead to systematic biases in the stellar masses, SFRs, and other galaxy properties. We discuss how surveys of galaxies at 3.5 < z < 6.5 with multi-object optical spectrographs on 25-m class telescopes (such as GMT/GMACS) will provide deep spectra to confirm high redshift targets from CANDELS, and improve the accuracy of derived quantities by lowering uncertainties in galaxy redshifts.
Heath Shipley, Texas A & M University
Poster: Spitzer Spectroscopy of Infrared-Luminous Galaxies: Diagnostics of AGN and Star Formation and Contribution to Total Infrared Luminosity
June 10 - 12, 2013
A key question is the nature of the Infrared (IR) luminous galaxies, and their role in the build up of stars and supermassive black holes in the distant Universe. Here, we present research using mid-IR spectroscopy (5-38 micron) from NASA's Spitzer Infrared Spectrograph (IRS) for a sample of 65 IR-luminous galaxies at redshifts 0.02 < z < 0.6. At these redshifts, the IR luminous galaxies in our sample are typical of those objects that dominate the cosmic IR luminosity density and the star-formation-rate density. The mid-IR spectra are minimally sensitive to dust obscuration, and they cover important molecular features (from polycyclic aromatic hydrocarbons, or PAHs) and atomic lines that are diagnostics of the amount of ionization from young stars and accreting supermassive black holes. We discuss how different mid-IR spectral lines trace the instantaneous star-formation rate (SFR), including the luminosity in the PAHs. Using these, we determine contribution to the total IR luminosity in galaxies that stems from star-formation versus that from AGN. I will also show a small subset of galaxies that indicate heavily dust-obscured AGN that are otherwise undetected based on common AGN-selection procedures. We discuss how deep optical and near-IR spectroscopy with instruments on 25m-class telescopes, such as GMACS and GMTIFS on the GMT, can be used to probe both star-formation and SMBH accretion in objects selected as AGN from their mid-IR colors as in our IRS sample (from Spitzer, but also WISE). We will discuss how such observations will allow us to better understand the properties of the IR-AGN.
Robert A Simcoe, MIT
Talk: The Role of GMT for Studies of Intergalactic Matter in the Early Universe
June 11, 2013 (3:00 PM - 3:20 PM)
Debopam Som, University of South Carolina
Talk: Magellan Spectroscopy of Sub-Damped Lyman-alpha QSO Absorbers at 2 < z < 3
June 11, 2013 (4:20 PM - 4:40 PM)
We present chemical abundance measurements of sub-Damped Lyman-alpha QSO absorbers at redshift 2 < z < 3 observed with the Magellan Inamori Kyocera Echelle (MIKE) spectrograph on the 6.5-m Magellan II Clay Telescope. Our data include absorption lines from several elements in various ionization stages, such as Mg I, Mg II, Al II, Al III, Si II, Si III, Si IV, S II, Mn II, Ni II, Cr II, Ti II, C II, C II*, C IV, and Zn II. The metallicities of the absorbers were inferred from the nearly undepleted elements Zn and S, and ionization corrections, if necessary, were applied. Combining our data with the literature sample, we present the most complete existing determination of the metallicity vs. redshift relation for sub-DLAs and DLAs. We confirm the suggestion from previous investigations that sub-DLA absorbers are, on average, more metal rich than DLAs and evolve faster. We also discuss the relative abundances (i. e [Zn/Fe], [Mn/Fe]) seen in the absorbers in this sample. We use the velocity width values for these sub-DLAs, as inferred from unsaturated metal absorption lines, to explore the velocity width vs. metallicity relation in sub-DLAs. We also report the first estimates of cooling rates in sub-DLA quasar absorbers based on the CII* column density measurements from our sample.
Rachel Somerville, Rutgers University
Invited Talk: Insights and Puzzles in Galaxy Formation
June 11, 2013 (8:30 AM - 9:00 AM)
Gordon J Stacey, Cornell University
Talk: The CCAT Telescope
June 10, 2013 (2:00 PM - 2:30 PM)
PDF, 2.19 MB
The CCAT telescope is a 25 m submillimeter telescope envisioned for a site near the summit of Cerra Chajnantor, in the Atacama desert in northern Chile. CCAT has an exceptionally large aperture with high surface accuracy and a wide field of view that will be located at an excellent site. Therefore, with the large format array cameras and spectrometers envisioned for the facility, we expect superb point source sensitivity and unrivaled mapping speed in the submillimeter telluric windows. I will discuss the characteristics of the CCAT facility including telescope and first light instrumentation, the primary science goals for the project, its current status and timeline, and finish with a discussion of the scientific synergies between CCAT and other contemporary faciliites. The CCAT project is a collaboration between Cornell University, Caltech, the University of Colorado, a consortium of Canadian Unversities (Dalhousie, McGill, McMaster, British Columbia, Calgary, Toronto, Waterloo, Western Ontario), the Universities of Cologne and Bonn, and Associated Universities, Incorporated, and the work is supported in part by the US National Science Foundation.
Albert Stebbins, Fermilab
Talk: What Can You Learn From Redshift Drift?
June 12, 2013 (3:10 PM - 3:30 PM)
Given enough time, enough photons, and enough objects one should be able to measure the systematic rate of change in the redshift of objects at cosmological distances. This can tell you something about, say, the gravitational repulsion of dark energy (as proposed by Loeb). I will present a variety of issues regarding the interpretation of such measurements including systematics.
Nicholas B Suntzeff, Texas A&M University
Invited Talk: Conference Summary
June 12, 2013 (3:30 PM - 4:00 PM)
Laura Trouille, Northwestern University and The Adler Planetarium
Poster: AGN Science with the LSST
June 10 - 12, 2013
The Large Synoptic Survey Telescope (LSST; http://lsst.org) will revolutionize our understanding of active galactic nuclei (AGN) and their environments. The decade-long survey will discover at least 10 million AGN across 18,000 square degrees on the sky, with between about 50 to 200 visits per source for each of the ugrizy filters. A combination of the LSST sub-arcsecond astrometry, six-band photometry, and unprecedented cadence will enable the most efficient AGN selection, with additional characterization through the use of sophisticated star-galaxy separation techniques. The time-domain nature of the survey will provide invaluable information on the physics of the AGN central engine, as well as on transient fueling events, and will allow real-time alerts that will trigger follow-up observations. Several LSST ''deep drilling'' fields will help discover the faintest AGN at high redshift, enhancing the value of current and planned multiwavelength pencil-beam surveys while providing hours-to-years temporal information on thousands of AGN. The wide ranges of both luminosity and redshift spanned by LSST, including the discovery of over 1000 quasars at z>6.5, will dramatically improve the quantification of the optical AGN luminosity function. Measurements of AGN clustering at high redshift will be used to determine the relationship between AGN and dark matter. The discovery of about 8000 gravitationally lensed quasars, including 1000 systems with measurable time delays, will place significantly tighter constraints on key cosmological parameters.
Michael S Turner, KICP, University of Chicago
Invited Talk: Welcome from KICP
June 10, 2013 (8:30 AM - 8:40 AM)
Branislav Vlahovic, North Carolina Central University
Talk: Is inflation really necessary in a closed Universe?
June 12, 2013 (2:50 PM - 3:10 PM)
PDF, 2.44 MB
The paradigm of LambdaCDM cosmology together with the concept of inflation explains the Universe evolution well. However, there are still a few concerns; the dark matter is not detected directly and the dark energy is not described theoretically on a satisfactory level. Within the FRW formalism we consider a model of the closed Universe (with the spherical space), filled with the additional perfect fluid with the constant parameter -1/3 in the linear equation of state (which may be called quintessence). We compare this model with the standard LambdaCDM one and answer the following question: can this additional fluid lead to light traveling between the antipodal points during the current age of the Universe? This possibility strongly affects the inflation scenario which may completely lose its necessity.
Matthew G Walker, Harvard-Smithsonian Center for Astrophysics
Talk: Galactic Dynamics and the Nature of Dark Matter
June 12, 2013 (11:30 AM - 11:50 AM)
Jian-Min Wang, Institute of High Energy Physics, Chinese Academy of Sciences
Talk: Super-Eddington accreting massive black holes as long-lived cosmological standards
June 12, 2013 (2:20 PM - 2:50 PM)
Super-Eddington accretion onto black holes makes the radiated emission tend to be saturated, showing that the disk luminosity is linearly proportional to black hole mass, but logarithmically to the accretion rates. Such a kind of super-Eddington accreting massive black hole (SEAMBHs) already appears as special populations of quasars and active galactic nuclei from Sloan Digital Sky Survey. This lends an opportunity to employ the SEAMBHs as new standards to measure the cosmic dynamics beyond the type Ia supernovae (i.e. redshift is larger than 1.5). The new rulers depends on accuracy of black hole mass through reverberation mapping observations of AGNs and quasars. I will present the progress in this subjects and show the future observations of GMT.
Risa Wechsler, Stanford University
Invited Talk: Probing the Dark Universe with Galaxies
June 12, 2013 (8:30 AM - 9:00 AM)
Rogier A. Windhorst, Arizona State University
Talk: Galaxy Assembly and AGN Growth with the Hubble WFC3 and with JWST
June 12, 2013 (10:10 AM - 10:30 AM)
PDF, 5.27 MB
We review some recent results on the topics of Galaxy Assembly and AGN Growth with the Hubble Space Telescope Wide Field Camera 3 (WFC3), and how the 6.5 meter James Webb Space Telescope (JWST) --- after its launch planned for 2018 --- will build on this work, well into the the epochs of First Light and Reionization. Time permitting, I will also summarize the critical complementary role that the new 20-30 meter class ground-based telescopes and the 6.5 meter JWST in L2 will play this next decade, as the 8-10 meter ground-based telescopes and the 2.4 meter Hubble have so successfully done in the last two decades.
Isak Wold, University of Wisconsin
Talk: Evolution of Lya Emitting Galaxies: Insights From a Flux-Limited GALEX Sample at z~1
June 11, 2013 (3:20 PM - 3:50 PM)
Yu-Zhong Wu, Institute of High Energy Physics, Chinese Academy of Sciences
Poster: The nuture of BPT diagrams in star-forming galaxies
June 10 - 12, 2013
Utilizing the observational data of 83,569 star-forming galaxies(SFGs) selected from the catalog of MPA-JHU emission-line measurements for the SDSS DR7, we firstly show the distribution of SFGs with increasing metallicities on the BPT diagrams, i.e., metallicity increasing in /nii$lambda$ 6584/H$alpha$ vs /oiii$lambda$5007/H$beta$ is inconsistent with that in /oi$lambda$6300/H$alpha$ vs /oiii$lambda$5007/H$beta$ or /sii$lambdalambda$6716, 6731/H$alpha$ vs /oiii$lambda$5007/H$beta$. Then we display the distribution between low metallicities (low /nii/H$alpha$) and high metallicities (high /nii/H$alpha$) on the /nii/H$alpha$ vs /oiii/H$beta$, and we also demonstrate them on the /oi/H$alpha$ vs /oiii/H$beta$ and the /sii/H$alpha$ vs /oiii/H$beta$. Moreover, we show and compare the distributions of /nii, /oi, /sii, and H$alpha$ fluxes between low metallicities and high metallicities, and we find that /nii/H$alpha$ ratio is a good metallicity indicator, while both /oi/H$alpha$ and /sii/H$alpha$ are not. Finally, using the model of a sequence of bursts, which is proposed by Coziol et al. (1999), we investigate the nature of the BPT diagram.
Haojing Yan, University of Missouri-Columbia
Talk: The Most Luminous Galaxies at z>7 from the Recent HST Surveys
June 10, 2013 (4:30 PM - 4:50 PM)
Ilsang Yoon, George Mason University
Talk: Bayesian Inference of Galaxy Structure in the Era of Large Surveys
June 11, 2013 (11:00 AM - 11:20 AM)
We introduce a new Bayesian MCMC approach for rigorous and reliable galaxy decomposition analysis of large statistical samples. Challenges in galaxy image decomposition will be illustrated and significant improvement of parameter inference and model selection using Bayesian MCMC will be shown. Also Bayesian census of bulge, disk and spheroid in local Universe using 2MASS galaxies will be introduced.