Search Publications
The Diversity of Massive Star Outbursts. I. Observations of SN2009ip, UGC 2773 OT2009-1, and Their Progenitors
Foley, Ryan J.; Levesque, Emily M.; Berger, Edo +5 more
Despite both being outbursts of luminous blue variables (LBVs), SN 2009ip and UGC 2773 OT2009-1 have very different progenitors, spectra, circumstellar environments, and possibly physical mechanisms that generated the outbursts. From pre-eruption Hubble Space Telescope images, we determine that SN 2009ip and UGC 2773 OT2009-1 have initial masses o…
Black Hole Mass Estimates Based on C IV are Consistent with Those Based on the Balmer Lines
Stern, D.; Kozłowski, S.; Quirrenbach, A. +39 more
Using a sample of high-redshift lensed quasars from the CASTLES project with observed-frame ultraviolet or optical and near-infrared spectra, we have searched for possible biases between supermassive black hole (BH) mass estimates based on the C IV, Hα, and Hβ broad emission lines. Our sample is based upon that of Greene, Peng, & Ludwig, expan…
X-ray spectroscopy of the Virgo Cluster out to the virial radius
Böhringer, H.; Simionescu, A.; Allen, S. W. +2 more
We present results from the analysis of a mosaic of 13 XMM-Newton pointings covering the Virgo Cluster from its centre northwards out to a radius r∼ 1.2 Mpc (∼4?5), reaching the virial radius and beyond. This is the first time that the properties of a modestly sized (Mvir∼ 1.4 × 1014 M⊙, kT∼ 2.3 keV), dynamically y…
Multiwavelength campaign on Mrk 509. IV. Optical-UV-X-ray variability and the nature of the soft X-ray excess
Kaastra, J. S.; Kriss, G. A.; Cappi, M. +8 more
We present the analysis of XMM-Newtonand Swiftoptical-UV and X-ray observations of the Seyfert-1/QSO
C-GOALS: Chandra observations of a complete sample of luminous infrared galaxies from the IRAS Revised Bright Galaxy Survey
Veilleux, S.; Sanders, D. B.; Surace, J. A. +11 more
We present X-ray data for a complete sample of 44 luminous infrared galaxies (LIRGs), obtained with the Chandra X-ray Observatory. These are the X-ray observations of the high luminosity portion of the Great Observatory All-sky LIRG Survey (GOALS), which includes the most luminous infrared selected galaxies, log (Lir/L⊙) ≥ 11…
Red Nuggets at High Redshift: Structural Evolution of Quiescent Galaxies Over 10 Gyr of Cosmic History
Glazebrook, Karl; McCarthy, Patrick J.; Yan, Haojing +15 more
We present an analysis of the size growth seen in early-type galaxies over 10 Gyr of cosmic time. Our analysis is based on a homogeneous synthesis of published data from 16 spectroscopic surveys observed at similar spatial resolution, augmented by new measurements for galaxies in the Gemini Deep Deep Survey. In total, our sample contains structura…
The HETDEX Pilot Survey. I. Survey Design, Performance, and Catalog of Emission-line Galaxies
Finkelstein, Steven L.; Schneider, Donald P.; Blanc, Guillermo A. +23 more
We present a catalog of emission-line galaxies selected solely by their emission-line fluxes using a wide-field integral field spectrograph. This work is partially motivated as a pilot survey for the upcoming Hobby-Eberly Telescope Dark Energy Experiment. We describe the observations, reductions, detections, redshift classifications, line fluxes, …
Characterizing precursors to stellar clusters with Herschel
Bernard, J. -P.; Testi, L.; Peretto, N. +9 more
Context. Despite their profound effect on the universe, the formation of massive stars and stellar clusters remains elusive. Recent advances in observing facilities and computing power have brought us closer to understanding this formation process. In the past decade, compelling evidence has emerged that suggests infrared dark clouds (IRDCs) may b…
Random forest automated supervised classification of Hipparcos periodic variable stars
Rimoldini, L.; Mowlavi, N.; Nienartowicz, K. +14 more
We present an evaluation of the performance of an automated classification of the Hipparcos periodic variable stars into 26 types. The sub-sample with the most reliable variability types available in the literature is used to train supervised algorithms to characterize the type dependencies on a number of attributes. The most useful attributes eva…
Magnetic Structure of Sunspots
Ichimoto, Kiyoshi; Borrero, Juan M.
In this review we give an overview about the current state-of-knowledge of the magnetic field in sunspots from an observational point of view. We start by offering a brief description of tools that are most commonly employed to infer the magnetic field in the solar atmosphere with emphasis in the photosphere of sunspots. We then address separately…