The Palermo<i>Swift</i>-BAT hard X-ray catalogue

Abstract

<i>Aims. <i/>We present the Palermo <i>Swift<i/>-BAT hard X-ray catalogue obtained from the analysis of data acquired during the first 39 months of the Swift mission.<i>Methods. <i/>We developed a dedicated software to perform the data reduction, mosaicking, and source detection of the BAT survey data. We analyzed the BAT dataset in three energy bands (14-150 keV, 14-30 keV, 14-70 keV), obtaining a list of 962 detections above a significance threshold of 4.8 standard deviations. The identification of the source counterparts was pursued using three strategies: cross-correlation with published hard X-ray catalogues, analysis of field observations of soft X-ray instruments, and cross-correlation with SIMBAD databases.<i>Results. <i/>The survey covers 90% of the sky down to a flux limit of <i>2.5<i/> 10<sup>-11<sup/> erg cm<sup>-2<sup/> s<sup>-1<sup/> and 50% of the sky down to a flux limit of <i>1.8<i/> 10<sup>-11<sup/> erg cm<sup>-2<sup/> s<sup>-1<sup/> in the 14-150 keV band. We derived a catalogue of 754 identified sources, of which % are extragalactic, % are Galactic objects, and % are already known X-ray or gamma ray emitters, whose nature has yet to be determined. The integrated flux of the extragalactic sample is of the cosmic X-ray background in the 14-150 keV range.