相关论文: Transient X-ray source population in the Magellani…

X-ray point sources in galaxies are dominated by X-ray binaries (XRBs) that are variables or transients and whether their variability would alter the X-ray luminosity functions (XLF) is still in debate. Here we report on NGC 7331 as an…

We analyze 18 sources that were found to show interesting properties of periodicity, very soft spectra and/or large long-term variability in X-rays in our project of classification of sources from the 2XMMi-DR3 catalog but were poorly…

We present Chandra X-ray Observatory ACIS-S3 X-ray imaging observations and VLT/FORS2 and Hubble Space Telescope optical observations of two low-density Galactic globular clusters; NGC 6366 and M55. We detect 16 X-ray sources with 0.5-6.0…

First results from a deep XMM-Newton observation of a field in the Large Magellanic Cloud (LMC) near the northern rim of the supergiant shell LMC 4 are presented. Spectral and temporal analyses of a sample of selected X-ray sources yielded…

We investigated four luminous supersoft X-ray sources (SSS) in the Magellanic Clouds suspected to have optical counterparts of Be spectral type. If the origin of the X-rays is in a very hot atmosphere heated by hydrogen burning in accreted…

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…

We have carried out an in-depth study of low-mass X-ray binaries (LMXBs) detected in the nearby lenticular galaxy NGC 3115, using the Megasecond Chandra X-Ray Visionary Project observation (total exposure time 1.1 Ms). In total we found 136…

The Advanced Satellite for Cosmology and Astrophysics (ASCA) has made multiple observations of the Small Magellanic Cloud (SMC). X-ray mosaic images in the soft (0.7--2.0 keV) and hard (2.0--7.0 keV) bands are separately constructed, and…

In an XMM-Newton raster observation of the bright Local Group spiral galaxy M 33 we study the population of X-ray sources (X-ray binaries, supernova remnants) down to a 0.2--4.5 keV luminosity of 10^35 erg/s -- more than a factor of 10…

We study populations of soft and super-soft X-ray sources in nearby galaxies of various morphological types with the special emphasis on characterizing populations of stable nuclear burning accreting WDs. Analysing the content of Chandra…

We examined 134 Chandra observations of the population of X-ray sources associated with globular clusters (GCs) in the central region of M31. These are expected to be X-ray binary systems (XBs), consisting of a neutron star or black hole…

Aims. M 31 has been completely imaged for the first time obtaining a luminosity lower limit ~10^35 erg s-1 in the 0.2-4.5 keV band. Our XMM-Newton EPIC survey combines archival observations with observations taken between June 2006 and…

We present a sample of hard X-ray selected candidate black holes (BHs) in 19 dwarf galaxies. BH candidates are identified by cross-matching a parent sample of ~44,000 local dwarf galaxies (M_stellar < 3 x 10^9 Msun, z<0.055) with the…

We have observed two low concentration Galactic globular clusters with the X-ray observatory XMM-Newton. We detect 47 faint X-ray sources in the direction of M 55 and 62 in the field of view of NGC 3201. Using the statistical Log N-Log S…

By analyzing the Chandra ACIS S3 data we studied the X-ray properties of the low-mass and high-mass X-ray binary populations in the nearby spiral galaxy NGC 5055. A total of 43 X-ray point sources were detected within the 2 effective radii,…

In this paper we investigate the X-ray spectra and X-ray spectral variability of compact X-ray sources for 3 Chandra observations of the Local Group galaxy M33. The observations are centered on the nucleus and the star forming region NGC…

We have created 0.3--10 keV, 13 year, unabsorbed luminosity lightcurves for 528 X-ray sources in the central 20' of M31. We have 174 Chandra observations spaced at ~1 month intervals thanks to our transient monitoring program, deeper…

From October 1999 to August 2002, 45 transient X-ray sources were detected in M31 by Chandra and XMM-Newton. We have performed spectral analysis of all XMM-Newton and Chandra ACIS detections of these sources, as well as flux measurements of…

We present the global X-ray properties of the point source population in the grand-design spiral galaxy M101, as seen with XMM-Newton. 108 X-ray sources are detected within the D25 ellipse of M101, of which ~24 are estimated to be…

The Chandra ACIS Survey of M33 (ChASeM33) has acquired 7 fields of ACIS data covering M33 with 200 ks of exposure in each field. A catalog from the first 10 months of data, along with archival Chandra observations dating back to the year…