Related papers: Automated classification of Chandra X-ray point so…
We report on a campaign to identify the counterparts to the population of X-ray sources discovered at the centre of our Galaxy by Wang et al.(2002) using Chandra. We have used deep, near infrared images obtained on VLT/ISAAC to identify…
We present the Chandra Multiwavelength Project (ChaMP) X-ray point source catalog with ~6,800 X-ray sources detected in 149 Chandra observations covering \~10 deg^2. The full ChaMP catalog sample is seven times larger than the initial…
VLT images in $BVI$ are used to identify the optical counterparts to bright CHANDRA X-ray points sources discovered by Kraft et al. (2001, ApJ, 560, 675) in NGC5128. Of a total of 111 X-ray point sources with L_X>2*10^{36} ergs/s present in…
A Chandra ACIS-S imaging observation of the nearby galaxy M81 (NGC 3031) reveals 9 luminous soft X-ray sources. The local environments, X-ray spectral properties, and X-ray light curves of the sources are presented and discussed in the…
Globular clusters host a variety of lower-luminosity ($L_X<10^{35}$ erg s$^{-1}$) X-ray sources, including accreting neutron stars and black holes, millisecond pulsars, cataclysmic variables, and chromospherically active binaries. In this…
A Chandra X-Ray Observatory ACIS-S imaging observation is used to study the population of X-ray sources in the nearby Sab galaxy M81 (NGC 3031). A total of 177 sources are detected with 124 located within the D25 isophote to a limiting…
In our search for ``hidden'' AGN we present results from a Chandra observation of the nearby cluster Abell 2255. Eight cluster galaxies are associated with point-like X-ray emission, and we classify these galaxies based on their X-ray,…
X-ray sources with very few counts can be identified with low-noise X-ray detectors such as ACIS onboard the Chandra X-ray Observatory. These sources are often too faint for parametric spectral modeling using well-established methods such…
We have studied the correlation between 2357 Chandra X-ray point sources in a 40 x 40 parsec field and ~20,000 infrared sources we observed in the corresponding subset of our 2 x 1.4 degree Spitzer/IRAC Galactic Center Survey at 3.6-8.0 um,…
We present $Chandra$ X-ray point source catalogs for 9 Hickson Compact Groups (HCGs, 37 galaxies) at distances $34 - 89$ Mpc. We perform detailed X-ray point source detection and photometry, and interpret the point source population by…
Hard X-ray observations are the most efficient way to discriminate accretion-powered sources from star-light. Furthermore, hard X-rays are less affected than other bands by obscuration. For these reasons the advent of imaging instruments…
The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) satellite has detected in excess of 1000 sources in the ~20-100 keV band during its surveys of the sky over the past 17 years. We obtained 5 ks observations of 15 unclassified…
As part of the Chandra Galactic Bulge Survey (GBS), we present a catalogue of optical sources in the GBS footprint. This consists of two regions centered at Galactic latitude b = 1.5 degrees above and below the Galactic Centre, spanning (l…
We present a search for nuclear X-ray emission in the brightest cluster galaxies (BCGs) of a sample of groups and clusters of galaxies extracted from the Chandra archive. The exquisite angular resolution of Chandra allows us to obtain…
We have conducted Chandra observations of ~2560 square arcmin (~131 kpc^2) of of M31, and find that the most luminous X-ray sources in our fields are in globular clusters (GCs). Of the 28 GC X-ray sources in our fields, 17 are newly…
We present an analysis of the ultraluminous X-ray source (ULX) population in 75 Virgo cluster late-type galaxies, including all those with a star formation rate >~ 1 M_{sun}/yr and a representative sample of the less star-forming ones. This…
The powerful combination of the Chandra X-ray telescope, the SCUBA submillimetre-wave camera and the gravitational lensing effect of the massive galaxy clusters A2390 and A1835 has been used to place stringent X-ray flux limits on six faint…
We report the discovery of eight X-ray sources with periodic variability in 487 ks of observations of the Galactic center with Chandra. The sources are identified from a sample of 285 objects detected with 100-4200 net counts. Their periods…
We obtain total galaxy X-ray luminosities, $L_X$, originating from individually detected point sources in a sample of 47 galaxies in 15 compact groups of galaxies (CGs). For the great majority of our galaxies, we find that the detected…
We present the X-ray source catalog for the Chandra monitoring observations of the elliptical galaxy, NGC 4649. The galaxy has been observed with Chandra ACIS-S3 in six separate pointings, reaching a total exposure of 299 ks. There are 501…