Search Publications
Self-Consistent Models of the AGN and Black Hole Populations: Duty Cycles, Accretion Rates, and the Mean Radiative Efficiency
Miralda-Escudé, Jordi; Weinberg, David H.; Shankar, Francesco
We construct evolutionary models of the populations of active galactic nuclei (AGNs) and supermassive black holes, in which the black hole mass function grows at the rate implied by the observed luminosity function, given assumptions about the radiative efficiency and the luminosity in Eddington units. We draw on a variety of recent X-ray and opti…
The ACS Fornax Cluster Survey. V. Measurement and Recalibration of Surface Brightness Fluctuations and a Precise Value of the Fornax-Virgo Relative Distance
Jordán, Andrés; Infante, Leopoldo; Tonry, John L. +6 more
We present (g 475 - z 850) color and z 850-band surface brightness fluctuations (SBFs) measurements for 43 early-type galaxies in the Fornax cluster imaged with the Hubble Space Telescope Advanced Camera for Surveys. These are combined with our earlier measurements for Virgo cluster galaxies to derive a revised, no…
The ACS Survey of Galactic Globular Clusters. VII. Relative Ages
Milone, Antonino P.; Anderson, Jay; Dotter, Aaron +13 more
The ACS Survey of Galactic globular clusters is a Hubble Space Telescope Treasury program designed to provide a new large, deep, and homogeneous photometric database. Based on observations from this program, we have measured precise relative ages for a sample of 64 Galactic globular clusters by comparing the relative position of the clusters' main…
The Spitzer Local Volume Legacy: Survey Description and Infrared Photometry
Dalcanton, J. J.; Walter, F.; Dale, D. A. +21 more
The survey description and the near-, mid-, and far-infrared flux properties are presented for the 258 galaxies in the Local Volume Legacy (LVL). LVL is a Spitzer Space Telescope legacy program that surveys the local universe out to 11 Mpc, built upon a foundation of ultraviolet, Hα, and Hubble Space Telescope imaging from 11HUGS (11 Mpc Hα and Ul…
UV Continuum Slope and Dust Obscuration from z ~ 6 to z ~ 2: The Star Formation Rate Density at High Redshift
Chary, R. -R.; Giavalisco, M.; van Dokkum, P. +6 more
We provide a systematic measurement of the rest-frame UV continuum slope β over a wide range in redshift (z ~ 2-6) and rest-frame UV luminosity (0.1 L* z = 3 to 2 L* z = 3) to improve estimates of the star formation rate (SFR) density at high redshift. We utilize the deep optical and infrared data (Advanced Camera for Surveys…
The Kiloparsec-scale Kinematics of High-redshift Star-forming Galaxies
Pettini, Max; Erb, Dawn K.; Shapley, Alice E. +4 more
We present the results of a spectroscopic survey of the kinematic structure of star-forming galaxies at redshift z ~ 2-3 using Keck/OSIRIS integral field spectroscopy. Our sample is comprised of 12 galaxies between redshifts z ~ 2.0 and 2.5 and one galaxy at z ~ 3.3 which are well detected in either Hα or [O III] emission. These galaxies are gener…
A Catalog of Broad Absorption Line Quasars in Sloan Digital Sky Survey Data Release 5
Brandt, W. N.; Shen, Yue; Hall, Patrick B. +9 more
We present a catalog of 5039 broad absorption line (BAL) quasars (QSOs) in the Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) QSO catalog that have absorption troughs covering a continuous velocity range >=2000 km s-1. We have fitted ultraviolet (UV) continua and line emission in each case, enabling us to report common diagnost…
The Evolutionary History of Lyman Break Galaxies Between Redshift 4 and 6: Observing Successive Generations of Massive Galaxies in Formation
Stark, Daniel P.; Ellis, Richard S.; Bunker, Andrew +4 more
We present new measurements of the evolution in the Lyman break galaxy (LBG) population between z sime 4 and z sime 6. By utilizing the extensive multiwavelength data sets available in the GOODS fields, we identify 2443 B, 506 V, and 137 i'-band dropout galaxies likely to be at z ≈ 4, 5, and 6. For the subset of dropouts for which reliable Spitzer…
Supernova Feedback Efficiency and Mass Loading in the Starburst and Galactic Superwind Exemplar M82
Heckman, Timothy M.; Strickland, David K.
We measure the net energy efficiency of supernova (SN) and stellar wind feedback in the starburst galaxy M82 and the degree of mass loading of the hot gas piston driving its superwind by comparing a large suite of one and two-dimensional hydrodynamical models to a set of observational constraints derived from hard X-ray observations of the starbur…
The Peculiar Solar Composition and Its Possible Relation to Planet Formation
Gustafsson, B.; Yong, D.; Asplund, M. +1 more
We have conducted a differential elemental abundance analysis of unprecedented accuracy (~0.01 dex) of the Sun relative to 11 solar twins from the Hipparcos catalog and 10 solar analogs from planet searches. We find that the Sun shows a characteristic signature with a ≈20% depletion of refractory elements relative to the volatile elements in compa…