Search Publications
XMM-Newton and Gemini Observations of Eight RASSCALS Galaxy Groups
Geller, Margaret J.; Mahdavi, Andisheh; Finoguenov, Alexis +2 more
We study the distribution of gas pressure and entropy in eight groups of galaxies belonging to the ROSAT All-Sky Survey/Center for Astrophysics Loose Systems (RASSCALS). We use archival and proprietary XMM-Newton observations, supplementing the X-ray data with redshifts derived from the literature; we also list 127 new redshifts measured with the …
The Stellar Content of Nearby Star-forming Galaxies. III. Unravelling the Nature of the Diffuse Ultraviolet Light
de Mello, Duilia; Aloisi, Alessandra; Meurer, Gerhardt R. +4 more
We investigate the nature of the diffuse intracluster ultraviolet light seen in 12 local starburst galaxies, using long-slit ultraviolet spectroscopy obtained with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). We take this faint intracluster light to be the field in each galaxy and compare its spectroscop…
The Gamma-Ray Giant Flare from SGR 1806-20: Evidence of Crustal Cracking via Initial Timescales
Kataria, D. O.; Zane, Silvia; Schwartz, Steven J. +6 more
Soft γ-ray repeaters (SGRs) are neutron stars that emit short (<~1 s) and energetic (<~1042 ergs s-1) bursts of soft γ-rays. Only four of them are currently known. Occasionally, SGRs have been observed to emit much more energetic ``giant flares'' (~1044-1045 ergs s-1). These are exceptio…
The DEEP2 Galaxy Redshift Survey: Discovery of Luminous, Metal-poor Star-forming Galaxies at Redshifts z ~ 0.7
Hoyos, C.; Koo, D. C.; Willmer, C. N. A. +2 more
We have discovered a sample of 17 metal-poor, yet luminous, star-forming galaxies at redshifts z~0.7. They were selected from the initial phase of the DEEP2 survey of 3900 galaxies and the Team Keck Redshift Survey (TKRS) of 1536 galaxies as those showing the temperature-sensitive [O III] λ4363 auroral line. These rare galaxies have blue luminosit…
X-Ray/Ultraviolet Observing Campaign of the Markarian 279 Active Galactic Nucleus Outflow: A Global-Fitting Analysis of the Ultraviolet Absorption
Laor, Ari; Scott, Jennifer E.; Kriss, Gerard A. +12 more
We present an analysis of the intrinsic UV absorption in the Seyfert 1 galaxy Mrk 279 based on simultaneous long observations with the Hubble Space Telescope (41 ks) and the Far Ultraviolet Spectroscopic Explorer (91 ks). To extract the line-of-sight covering factors and ionic column densities, we separately fit two groups of absorption lines: the…
The Far-Infrared Emission Line and Continuum Spectrum of the Seyfert Galaxy NGC 1068
Smith, Howard A.; González-Alfonso, Eduardo; Spinoglio, Luigi +2 more
We report on the analysis of the first complete far-infrared spectrum (43-197 µm) of the Seyfert 2 galaxy NGC 1068 as observed with the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). In addition to the seven expected ionic fine-structure emission lines, the OH rotational lines at 79, 119, and 163 µm w…
INTEGRAL SPI Limits on Electron-Positron Annihilation Radiation from the Galactic Plane
Hornstrup, A.; Parmar, A. N.; Güdel, M. +25 more
The center of our Galaxy is a known strong source of electron-positron 511 keV annihilation radiation. Thus far, however, there have been no reliable detections of annihilation radiation outside of the central radian of our Galaxy. One of the primary objectives of the INTEGRAL (International Gamma-Ray Astrophysics Laboratory) mission, launched in …
The Hot Intergalactic Medium-Galaxy Connection: Two Strong O VI Absorbers in the Sight Line toward PG 1211+143
Shull, J. Michael; Stocke, John T.; Tumlinson, Jason +1 more
We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) and Far Ultraviolet Spectroscopic Explorer (FUSE) spectra of the QSO PG 1211+143 (zem=0.081) and a galaxy survey of the surrounding field. This sight line shows two strong intergalactic absorption systems at cz~=15,300 and 19,300 km s-1. This …
First Optical Images of Circumstellar Dust Surrounding the Debris Disk Candidate HD 32297
Kalas, Paul
Near-infrared imaging with the Hubble Space Telescope recently revealed a circumstellar dust disk around the A star HD 32297. Dust-scattered light is detected as far as 400 AU radius, and the linear morphology is consistent with a disk ~10° away from an edge-on orientation. Here we present the first optical images that show the dust-scattered ligh…
Non-LTE Model Atmosphere Analysis of the Large Magellanic Cloud Supersoft X-Ray Source CAL 83
Rasmussen, Andrew P.; Paerels, Frits; Hubeny, Ivan +3 more
We present a non-LTE (NLTE) model atmosphere analysis of Chandra High Resolution Camera (HRC-S) and Low Energy Transmission Grating (LETG) and XMM-Newton Reflection Grating Spectrometer (RGS) spectroscopy of the prototypical supersoft source CAL 83 in the Large Magellanic Cloud. Taken with a 16 month interval, the Chandra and XMM-Newton spectra ar…