Search Publications
Star Formation in the Early Universe: Beyond the Tip of the Iceberg
Greiner, J.; Kouveliotou, C.; Fruchter, A. S. +18 more
We present late-time Hubble Space Telescope (HST) imaging of the fields of six Swift gamma-ray bursts (GRBs) lying at 5.0 <~ z <~ 9.5. Our data include very deep observations of the field of the most distant spectroscopically confirmed burst, GRB 090423, at z = 8.2. Using the precise positions afforded by their afterglows, we can place strin…
The M31 Velocity Vector. I. Hubble Space Telescope Proper-motion Measurements
Anderson, Jay; van der Marel, Roeland P.; Sohn, Sangmo Tony
We present the first proper-motion (PM) measurements for the galaxy M31. We obtained new V-band imaging data with the Hubble Space Telescope ACS/WFC and the WFC3/UVIS instruments of three fields: a spheroid field near the minor axis, an outer disk field along the major axis, and a field on the Giant Southern Stream. The data provide five to seven …
Deep Absorption Line Studies of Quiescent Galaxies at z ~ 2: The Dynamical-mass-Size Relation and First Constraints on the Fundamental Plane
Grillo, C.; Toft, S.; Zibetti, S. +4 more
We present dynamical and structural scaling relations of quiescent galaxies at z = 2, including the dynamical-mass-size relation and the first constraints on the fundamental plane (FP). The backbone of the analysis is a new, very deep Very Large Telescope/X-shooter spectrum of a massive, compact, quiescent galaxy at z = 2.0389. We detect the conti…
High-velocity Outflows without AGN Feedback: Eddington-limited Star Formation in Compact Massive Galaxies
Moustakas, John; Coil, Alison L.; Rudnick, Gregory H. +5 more
We present the discovery of compact, obscured star formation in galaxies at z ~ 0.6 that exhibit >~ 1000 km s-1 outflows. Using optical morphologies from the Hubble Space Telescope and infrared photometry from the Wide-field Infrared Survey Explorer, we estimate star formation rate (SFR) surface densities that approach ΣSFR
Dynamical Measurements of Black Hole Masses in Four Brightest Cluster Galaxies at 100 Mpc
Ma, Chung-Pei; Graham, James R.; Gebhardt, Karl +5 more
We present stellar kinematics and orbit superposition models for the central regions of four brightest cluster galaxies, based upon integral-field spectroscopy at Gemini, Keck, and McDonald Observatories. Our integral-field data span radii from <100 pc to tens of kiloparsecs, comparable to the effective radius of each galaxy. We report black ho…
Panchromatic Observations of SN 2011dh Point to a Compact Progenitor Star
Sakamoto, T.; Zhang, X.; Cline, T. +32 more
We report the discovery and detailed monitoring of X-ray emission associated with the Type IIb SN 2011dh using data from the Swift and Chandra satellites, placing it among the best-studied X-ray supernovae (SNe) to date. We further present millimeter and radio data obtained with the Submillimeter Array, the Combined Array for Research in Millimete…
The Star Formation History and Metal Content of the Green Peas. New Detailed GTC-OSIRIS Spectrophotometry of Three Galaxies
Amorín, R.; Pérez-Montero, E.; Vílchez, J. M. +1 more
We present deep broadband imaging and long-slit spectroscopy of three compact, low-mass starburst galaxies at redshift z ~ 0.2-0.3, also referred to as Green Peas (GP). We measure physical properties of the ionized gas and derive abundances for several species with high precision. We find that the three GPs display relatively low extinction, low o…
Evolution of the Quasar Luminosity Function over 3 < z < 5 in the COSMOS Survey Field
Salvato, M.; Hasinger, G.; Capak, P. +10 more
We investigate the high-redshift quasar luminosity function (QLF) down to an apparent magnitude of I AB = 25 in the Cosmic Evolution Survey (COSMOS). Careful analysis of the extensive COSMOS photometry and imaging data allows us to identify and remove stellar and low-redshift contaminants, enabling a selection that is nearly complete fo…
Information Content of Exoplanetary Transit Spectra: An Initial Look
Line, Michael R.; Zhang, Xi; Yung, Yuk L. +3 more
It has been shown that spectroscopy of transiting extrasolar planets can potentially provide a wealth of information about their atmospheres. Herein, we set up the inverse problem in spectroscopic retrieval. We use nonlinear optimal estimation to retrieve the atmospheric state (pioneered for Earth sounding by Rodgers). The formulation quantifies t…
A Jet Break in the X-Ray Light Curve of Short GRB 111020A: Implications for Energetics and Rates
Troja, E.; Sakamoto, T.; Berger, E. +8 more
We present broadband observations of the afterglow and environment of the short GRB 111020A. An extensive X-ray light curve from Swift/XRT, XMM-Newton, and Chandra, spanning ~100 s to 10 days after the burst, reveals a significant break at δt ≈ 2 days with pre- and post-break decline rates of α X, 1 ≈ -0.78 and α X, 2 <~ -…