相关论文: A Chandra X-ray census of the interacting binaries…

Open clusters belonging to star-forming complexes are the leftovers from the initial stellar generations. The study of these young systems provides constraints to models of star formation and evolution as well as to the properties of the…

We present results from a 34 ks Chandra/ACIS-S observation of the nearby (d=3.1 Mpc) lenticular galaxy NGC 5102, previously shown to have an unusually low X-ray luminosity. We detect eleven X-ray point sources within the the $D_{25}$…

We investigate the spatial coincidence of ultra-luminous X-ray sources (ULXs) with young massive stellar clusters. In particular we perform astrometry on Chandra and HST data of two ULXs that are possibly associated with such clusters. To…

We present the first high spatial resolution Chandra X-ray study of NGC 2244, the 2 Myr old stellar cluster immersed in the Rosette Nebula. Over 900 X-ray sources are detected; 77% have optical or FLAMINGOS near-infrared (NIR) stellar…

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…

We present new Chandra observations of seven luminous quasars at $z>6.5$. Combined with archival Chandra observations of all other known quasars, they form nearly complete X-ray observations of all currently known $z\sim7$ quasars with…

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 report on results of a 96.7 ks Chandra observation of one of the youngest, most embedded and massive young stellar clusters studied in X-rays - RCW 38. We detect 460 sources in the field of which 360 are confirmed to be associated with…

The high stellar densities in the cores of globular clusters cause significant stellar interactions. These stellar interactions can produce close binary mass-transferring systems involving compact objects and their progeny, such as X-ray…

We have carried out a Chandra observation of the globular cluster M54. We detected 7 sources located within the half-mass radius of M54, at a flux limit of 1.5x10^-15 erg/s/cm in the 0.3-8 keV energy band. The spatial distribution and the…

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…

Recently an unidentified emission line at 3.55 keV has been detected in X-ray spectra of clusters of galaxies. The line has been discussed as a possible decay signature of 7.1 keV sterile neutrinos, which have been proposed as a dark matter…

The relatively nearby (distance=24.1 Mpc) elliptical galaxy NGC821, hosting a central massive black hole but inactive at all wavelengths, was observed with Chandra for a total exposure of 230 ksec, to search for nuclear emission and gas…

We present a weak-lensing analysis of the z=1.4 galaxy cluster XMMU J2235.3-2557, based on deep Advanced Camera for Surveys images. Despite the observational challenge set by the high redshift of the lens, we detect a substantial lensing…

We present an analysis of the X-ray properties of a sample of solar- and late-type field stars identified in the Chandra Cosmic Evolution Survey (COSMOS), a deep (160ks) and wide (0.9 deg2) extragalactic survey. The sample of 60 sources was…

We analyzed archival Chandra X-ray observations of the central portion of the 30 Doradus region in the Large Magellanic Cloud. The image contains 20 X-ray point sources with luminosities between $5 \times 10^{32}$ and $2 \times 10^{35}$ erg…

Using new Chandra X-ray observations and existing XMM-Newton X-ray and Hubble far ultraviolet observations, we aim to detect and identify the faint X-ray sources belonging to the Galactic globular cluster NGC 2808 in order to understand…

We report on the discovery of a galaxy cluster at z = 1.490 originally selected as an extended X-ray source in the XMM-Newton Distant Cluster Project. Further observations carried out with the VLT-FORS2 spectrograph allowed the…

We report the discovery of an X-ray pulsar in the young, massive Galactic star cluster Westerlund 1. We detected a coherent signal from the brightest X-ray source in the cluster, CXO J164710.2-455216, during two Chandra observations on 2005…

We investigate low mass X-ray binaries (LMXBs) in the M31 globular cluster (GC) system using data from the 2XMMi catalogue. These X-ray data are based on all publicly available XMM-Newton observations of the galaxy. This new survey provides…