Related papers: Galactic centre X-ray sources
We present new optical spectroscopy of 20 candidate counterparts of 17 X-ray sources in the direction of the M31 disc. By comparing the X-ray catalogue from the XMM-Newton survey of M31 with star catalogues from the Local Group Galaxy…
The X-ray source populations within galaxies are typically difficult to identify and classify from X-ray data alone. We are able to break through this barrier by combining deep new Chandra ACIS-I observations with extensive Hubble Space…
The Chandra data archive after eight years' accumulation is a treasure for various studies, and in this paper we exploit this valuable resource to study the X-ray point source populations in nearby galaxies. By December 14, 2007, 383…
We discuss radio sources in the Chandra Galactic Bulge survey region. By cross-matching the X-ray sources in this field with the NVSS archival data, we find 12 candidate matches. We present a classification scheme for radio/X-ray matches in…
The scattering diameters of Sgr A* and several nearby OH masers (~ 1" at 1 GHz) indicate that a region of enhanced scattering is along the line of sight to the Galactic center. The scattering diameter of an extragalactic source seen through…
The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra program that has imaged the central 0.9 deg^2 of the COSMOS field down to limiting depths of 1.9 10^-16 erg cm^-2 s-1 in the 0.5-2 keV band, 7.3 10^-16 erg cm^-2 s^-1 in the…
I review our recent Chandra surveys of the center region of the Milky Way and other nearby edge-on galaxies. Our Galactic center survey provides an unprecedented high-resolution, broad-band X-ray panorama of a 0.8x2 square degree swath…
We searched in the public archive of the Chandra X-ray Observatory as of March 2016 and assembled a sample of 719 galaxies within 50 Mpc with ACIS observations available. By cross-correlation with the optical or near-infrared nuclei of…
We present several models for IRS 13E, an infrared, mm and X-ray source in the Galactic Center. Our favored interpretation is that of an early-type binary with strong colliding winds emission. This naturally explains the observed X-ray…
We present the results of the identification of six objects from the ASCA Galactic center and Galactic plane surveys: AXJ173548-3207, AXJ173628-3141, AXJ1739.5-2910, AXJ1740.4-2856, AXJ1740.5-2937, AXJ1743.9-2846. Chandra, XMM-Newton, and…
We revisit the association of unidentified Galactic plane EGRET sources with tracers of recent massive star formation and death. Up-to-date catalogs of OB associations, SNRs, young pulsars, HII regions and young open clusters were used in…
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 the results of our search for optical counterparts to high-mass X-ray transient sources discovered by various X-ray missions. We obtained CCD images of the X-ray fields through BVR and Halpha filters in order to identify…
A significant fraction ($\sim 30$ %) of the high-energy gamma-ray sources listed in the second $\textit{Fermi}$ LAT (2FGL) catalog are still of unknown origin, being not yet associated with counterparts at lower energies. In order to…
Today's sensistive, high resolution Chandra X-ray observations allow the study of many populations of X-ray sources. The traditional astronomical tools of photometric diagrams and luminosity functions are now applied to these populations,…
Our neighbouring large spiral galaxy, the Andromeda galaxy (M 31 or NGC 224), is an ideal target to study the X-ray source population of a nearby galaxy. NuSTAR observed the central region of M 31 in 2015 and allows studying the population…
The nature of a substantial percentage (about one fifth) of hard X-ray sources discovered with the BAT instrument onboard the Neil Gehrels Swift Observatory (hereafter Swift) is unknown because of the lack of an identified longer-wavelength…
Identifying gamma-ray sources in the Galaxy is hampered by their poor localization, source confusion, and the large variety of potential emitters. Neutron stars and their environment offer various ways to power gamma-ray sources: pulsed…
We report on the Chandra X-ray Observatory ACIS-S3 imaging observation of the Galactic globular cluster M4 (NGC 6121). We detect 12 X-ray sources inside the core and 19 more within the cluster half-mass radius. The limiting luminosity of…
X-ray appearance of normal galaxies is mainly determined by X-ray binaries powered by accretion onto a neutron star or a stellar mass black hole. Their populations scale with the star-formation rate and stellar mass of the host galaxy and…