The Brera multi-scale wavelet Chandra survey

Abstract

We present the BMW-Chandra source catalogue drawn from essentially all Chandra ACIS-I pointed observations with an exposure time in excess of 10 ks public as of March 2003 (136 observations). Using the wavelet detection algorithm developed by Lazzati et al. (1999) and Campana et al. (1999), which can characterise both point-like and extended sources, we identified 21 325 sources. Among them, 16 758 are serendipitous, i.e. not associated with the targets of the pointings, and do not require a non-automated analysis. This makes our catalogue the largest compilation of Chandra sources to date. The 0.5-10 keV absorption corrected fluxes of these sources range from ∼3 × 10 −16 to 9 × 10 −12 erg cm −2 s −1 with a median of 7 × 10 −15 erg cm −2 s −1 . The catalogue consists of count rates and relative errors in three energy bands (total, 0.5-7 keV; soft, 0.5-2 keV; and hard, 2-7 keV), and source positions relative to the highest signal-to-noise detection among the three bands. The wavelet algorithm also provides an estimate of the extension of the source. We include information drawn from the headers of the original files, as well, and extracted source counts in four additional energy bands, SB1 (0.5-1 keV), SB2 (1-2 keV), HB1 (2-4 keV), and HB2 (4-7 keV). We computed the sky coverage for the full catalogue and for a subset at high Galactic latitude (| b | > 20• ). The complete catalogue provides a sky coverage in the soft band (0.5-2 keV, S /N = 3) of ∼8 deg 2 at a limiting flux of ∼10 −13 erg cm −2 s −1 , and ∼2 deg 2 at a limiting flux of ∼10 −15 erg cm −2 s −1 . Furthermore, we present the results of the cross-match with existing catalogues at different wavelengths (FIRST, IRAS, 2MASS, GSC2, and ChaMP). The total numbers of matches with the FIRST, IRASPSC, 2MASS, and GSC2 catalogues obtained after a closest-distance selection are 13, 87, 6700, and 4485, respectively.

Gamma-Ray Bursts in theSwiftEra

“…None of the detections were of high statistical significance, but, combined, were of some credibility. Swift has not found any significant line features in comprehensive observations of the X-ray afterglow of more than 200 GRBs (Romano et al 2008). Hurkett et al (2008) also made a very detailed Swift X-ray line search, with no positive result.…”

1SXPS: A DEEP SWIFT X-RAY TELESCOPE POINT SOURCE CATALOG WITH LIGHT CURVES AND SPECTRA

“…The combination of sensitivity and sky coverage of this catalog means it occupies the area of parameter space between the deep-and-narrow surveys such as 3XMM-DR4, 1CSC (Evans et al 2010) and the Chandra BMW catalog (Romano et al 2008); and the shallow-and-wide surveys such as the Rosat All-Sky Survey (Voges et al…”

A MaxBCG Catalog of 13,823 Galaxy Clusters from the Sloan Digital Sky Survey

“…As a result, the total number of groups and clusters yet detected in X-rays is modest; there are only 1579 objects in the BAX database, a compendium of all X-ray groups and clusters detected as of 2004 (Sadat et al 2004). With no future all-sky X-ray survey planned, it is unlikely that the number of X-rayYdetected clusters will increase substantially over the next decade, although important contributions will be made by serendipitous surveys in the XMM-Newton and Chandra archives (Romer et al 2001;Green et al 2004;Romano et al 2004).…”