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A Complete Sample of Ultraluminous X-Ray Source Host Galaxies
One hundred seven ultraluminous X-ray sources (ULXs) with 0.3-10.0 keV luminosities in excess of 10{sup 39} erg s{sup -1} are identified in a complete sample of 127 nearby galaxies. The sample
Ultraluminous X-ray sources in the Chandra and XMM-Newton era
Abstract Ultraluminous X-ray sources (ULXs) are accreting black holes that may contain the missing population of intermediate mass black holes or reflect super-Eddington accretion physics. Ten years
A mass of less than 15 solar masses for the black hole in an ultraluminous X-ray source
The results demonstrate that in P13, soft thermal emission and spectral curvature are indeed signatures of supercritical accretion, and by analogy, ultraluminousX-ray sources with similar X-ray spectra and luminosities can be explained by super critical accretion onto massive stellar-mass black holes.
Quasi-periodic Variability in NGC 5408 X-1
We report the discovery with XMM-Newton of quasi-periodic variability in the 0.2-10 keV X-ray flux from the ULX NGC 5408 X-1. The average power spectrum of all EPIC-pn data reveals a strong 20 mHz
Detection of the Tip of the Red Giant Branch in NGC 5128
We present a color-magnitude diagram of more than 10,000 stars in the halo of the galaxy NGC 5128 (Centaurus A), based on WFPC2 images through V-band and I-band filters. The position of the red giant
Long-term X-ray variability of Swift J1644+57
We studied the X-ray timing and spectral variability of the X-ray source Sw J1644+57, a candidate for a tidal disruption event. We have separated the long-term trend (an initial decline followed by a
Variable Partial Covering and A Relativistic Iron Line in NGC 1365
We present a complete analysis of the hard X-ray (2-10 keV) properties of the Seyfert galaxy NGC 1365, based on a 60 ks XMM-Newton observation performed in 2004 January. The two main results are as
A wide star–black-hole binary system from radial-velocity measurements
Radial-velocity measurements of a Galactic B-type star show a dark companion that seems to be a black hole of about 68 solar masses, in a widely spaced binary system.
Accretion and nuclear activity of quiescent supermassive black holes. I. X-ray study
We have studied the nuclear activity in a sample of six quiescent early-type galaxies, with new Chandra data and archival HST optical images. Their nuclear sources have X-ray luminosities ~1038-1039
The ultraluminous X-ray source NGC 1313 X-2. Its optical counterpart and environment
NGC 1313 X-2 is one of the brightest ultraluminous X-ray sources in the sky, at both X-ray and optical wavelengths; therefore, quite a few studies of available ESO VLT and HST data have appeared in