VizieR Online Data Catalog: Swift X-ray Telescope Cluster Survey. II. (Tozzi+, 2014)

In Paper I we considered the Swift/XRT archive from February 2005 to April 2010, including 336 fields in the corresponding GRB positions, with Galactic latitude |b|>20°, to avoid crowded fields and strong Galactic absorption. We followed a standard data reduction procedure by means of the xrtpipeline task of the current release of the HEADAS software (version v6.8) with the most updated calibration (CALDB version 20111031, Nov. 2011). Then, we proceeded with a customized data reduction, aimed at optimizing our data to the detection of extended sources. The most important aspect of this step is the reduction of the background thanks to the exclusion of the intense GRB emission at the beginning of each observation, after a careful investigation of the background light curves.

(2 data files).