相关论文: Faint Extended X-ray Sources: A new Large Area Sur…

We present a new cluster-finding algorithm based on a combination of the Voronoi Tessellation and Friends-Of-Friends methods. The algorithm utilises probability distribution functions derived from a photometric redshift analysis and is…

Gamma ray observations from a few hundred MeV up to tens of TeV are a valuable tool for studying particle acceleration and diffusion within our galaxy. Constructing a coherent physical picture of particle accelerators such as supernova…

Large-scale fluctuations of the X-ray background are investigated using the ROSAT All-Sky Survey. The autocorrelation function of the extragalactic background at 1 keV is determined at separations 0.1 - 40 deg. We detect a significant…

(abridged) We present a new sample of X-ray selected galaxy groups and clusters serendipitously observed with Swift and the X-ray Telescope (XRT). We searched the XRT archive for extended sources among 336 GRB fields with galactic latitude…

We present the revised catalog of galaxy clusters detected as extended X-ray sources in the 160 Square Degree ROSAT Survey, including spectroscopic redshifts and X-ray luminosities for 200 of the 201 members. The median redshift is z~0.25…

Some indications for tension have long been identified between cosmological constraints obtained from galaxy clusters and primary CMB measurements. Typically, assuming the matter density and fluctuations, as parameterized with Omega_m and…

We present the Bright SHARC (Serendipitous High-Redshift Archival ROSAT Cluster) Survey, which is an objective search for serendipitously detected extended X-ray sources in 460 deep ROSAT PSPC pointings. The Bright SHARC Survey covers an…

We present deep K-band imaging at the positions of four very faint X-ray sources found in the UK ROSAT Deep Survey to have no optical counterpart brighter than R~23. Likely identifications are found within the ROSAT error circle in all four…

X-ray extragalactic surveys are ideal laboratories for the study of the evolution and clustering of active galactic nuclei (AGN). The XXL Survey spans two fields of a combined 50 $deg^2$ observed for more than 6Ms with XMM-Newton, occupying…

We report results of a serendipitous hard X-ray (3--20 keV), nearly all-sky (|b|>10deg) survey based on RXTE/PCA observations performed during satellite reorientations in 1996--2002. The survey is 80% (90%) complete to a 4$\sigma$ limiting…

We present the results of a program to acquire high-quality optical spectra of X-ray sources detected in the E-CDF-S and its central area. New spectroscopic redshifts are measured for 283 counterparts to Chandra sources with deep exposures…

In this paper, a review is given of methods useful for XMM-Newton EPIC data analysis of extended sources, along with some applications to a bright massive cluster of galaxies at z=0.2, Abell 209. This may constitute an introduction to that…

We present optical candidates for 75 X-ray sources in a $\sim 1$ deg$^2$ overlapping region with the medium deep ROSAT survey. These candidates are selected using the multi-color CCD imaging observations made for the T329 field of the…

We search for unresolved X-ray emission from lensed sources in the FOV of 11 CLASH clusters with Chandra data. We consider the solid angle in the lens plane corresponding to a magnification $\mu>1.5$, that amounts to a total of ~100…

We introduce an algorithm to estimate the redshift distribution of a sample of galaxies selected photometrically given a subsample with measured spectroscopic redshifts. The approach uses a non-parametric Voronoi tessellation density…

[Abridged] Sub-mm observations of the William Herschel Deep Field using LABOCA revealed possible counterparts for 2 X-ray absorbed QSOs. The aim here is to exploit EVLA imaging at 8.4 GHz to establish the QSOs as radio/sub-mm sources. The…

Investigations of the cluster environment of radio sources have not shown a correlation between radio power and degree of clustering. However, it has been demonstrated that extended X-ray luminosity and galaxy clustering do exhibit a…

We present the first results of a spectroscopic survey of faint lensed galaxie s in the core of the galaxy cluster AC114 (z=0.312) obtained from observations w ith the FORS1 spectrograph mounted on the VLT-Antu. The galaxies were chose n in…

Optical spectroscopy has enabled us to identify the optical counterparts to over 200 faint X-ray sources to a flux limit of S_(0.5-2keV)=4x10^-15 erg s^-1 cm^-2 on 5 deep ROSAT fields. Here we present a spectral analysis of all the X-ray…

We present the results of a systematic search for point-like and moderately extended soft (0.1-2.4 keV) X-ray sources in a raster of nine pointings covering a field of 8.95 deg^2 and performed with the ROSAT PSPC between October 1991 and…