Search Publications
Constraining Black Hole Spin via X-Ray Spectroscopy
Brenneman, Laura W.; Reynolds, Christopher S.
We present an analysis of the observed broad iron line feature and putative warm absorber in the long 2001 XMM-Newton observation of the Seyfert 1.2 galaxy MCG -06-30-15. The new kerrdisk model we have designed for simulating line emission from accretion disk systems allows black hole spin to be a free parameter in the fit, enabling the user to fo…
A Long, Hard Look at the Low/Hard State in Accreting Black Holes
Wijnands, R.; Fabian, A. C.; Miller, J. M. +5 more
We present the first results of coordinated multiwavelength observations of the Galactic black hole GX 339-4 in a canonical low/hard state, obtained during its 2004 outburst. XMM-Newton observed the source for two revolutions, or approximately 280 ks; RXTE monitored the source throughout this long stare. The resulting data offer the best view yet …
Constraints on the Physics of Type Ia Supernovae from the X-Ray Spectrum of the Tycho Supernova Remnant
Hughes, John P.; Hwang, Una; Badenes, Carles +2 more
In this paper we use high-quality X-ray observations from XMM-Newton and Chandra to gain new insights into the explosion that originated Tycho's supernova 433 yr ago. We perform a detailed comparison between the ejecta emission from the spatially integrated X-ray spectrum of the supernova remnant and current models for Type Ia supernova explosions…
The Hard X-Ray Spectral Slope as an Accretion Rate Indicator in Radio-quiet Active Galactic Nuclei
Maiolino, Roberto; Brandt, W. N.; Kaspi, Shai +2 more
We present new XMM-Newton observations of two luminous and high accretion rate radio-quiet active galactic nuclei (AGNs) at z~2. Together with archival X-ray and rest-frame optical spectra of three sources with similar properties, as well as 25 moderate-luminosity radio-quiet AGNs at z<0.5, we investigate, for the first time, the dependence of …
Chandra and XMM-Newton Observations of a Sample of Low-Redshift FR I and FR II Radio Galaxy Nuclei
Hardcastle, M. J.; Birkinshaw, M.; Worrall, D. M. +2 more
We present spectral results from Chandra and XMM-Newton observations of a sample of 22 low-redshift (z<0.1) radio galaxies and consider whether the core emission originates from the base of a relativistic jet, or an accretion flow, or contains contributions from both. We find correlations between the unabsorbed X-ray, radio, and optical fluxes …
The XMM Cluster Survey: A Massive Galaxy Cluster at z = 1.45
Conselice, Christopher J.; Hilton, Matt; Stanford, S. A. +14 more
We report the discovery of XMMXCS J2215.9-1738, a massive galaxy cluster at z=1.45, which was found in the XMM Cluster Survey. The cluster candidate was initially identified as an extended X-ray source in archival XMM data. Optical spectroscopy shows that six galaxies within a ~60" diameter region lie at z=1.45+/-0.01. Model fits to the X-ray spec…
A Multiwavelength Study of Sgr A*: The Role of Near-IR Flares in Production of X-Ray, Soft γ-Ray, and Submillimeter Emission
Dowell, C. D.; Bélanger, G.; Goldwurm, A. +8 more
Although Sgr A* is known to be variable in radio, millimeter, near-IR, and X-rays, the correlation of the variability across its spectrum has not been fully studied. Here we describe highlights of the results of two observing campaigns in 2004 to investigate the correlation of flare activity in different wavelength regimes, using a total of nine g…
Scaling Mass Profiles around Elliptical Galaxies Observed with Chandra and XMM-Newton
Fukazawa, Y.; Botoya-Nonesa, J. G.; Pu, J. +2 more
We investigated the dynamical structure of 53 elliptical galaxies using the Chandra archival X-ray data. In X-ray-luminous galaxies, temperature increases with radius and gas density is systematically higher at the optical outskirts, indicating the presence of a significant amount of the group-scale hot gas. In contrast, X-ray-dim galaxies show a …
A ``Combination Nova'' Outburst in Z Andromedae: Nuclear Shell Burning Triggered by a Disk Instability
Sokoloski, J. L.; Filippenko, A. V.; Charles, P. A. +11 more
We describe observational evidence for a new kind of interacting binary star outburst that involves both an accretion instability and an increase in thermonuclear shell burning on the surface of an accreting white dwarf. We refer to this new type of eruption as a combination nova. In late 2000, the prototypical symbiotic star Z Andromedae brighten…
A Chandra Survey of Early-Type Galaxies. I. Metal Enrichment in the Interstellar Medium
Humphrey, Philip J.; Buote, David A.
We present a Chandra study of the emission-weighted metal abundances in 28 early-type galaxies, spanning ~3 orders of magnitude in X-ray luminosity (LX). We report constraints for Fe, O, Ne, Mg, Si, S, and Ni. We find no evidence of the very subsolar Fe abundance (ZFe) historically reported, confirming a trend in recent obser…