Astronomy and Astrophysics, volume 520, A47-47 (2010/9-2)
The blazar content in the Swift-BAT hard X-ray sky.
MASELLI A., CUSUMANO G., MASSARO E., LA PAROLA V., SEGRETO A. and SBARUFATTI B.
Abstract (from CDS):
We present the results from a study of the blazar content in the 15-150keV map of the entire sky obtained analysing 39 months of data collected by the BAT telescope aboard the Swift satellite. We performed a cross-correlation of the significance map, obtained with a dedicated highly efficient algorithm for data processing and image reconstruction of the BAT survey data, with the blazar population of the Roma-BZCAT. After corrections for source confusion and spurious detections, we found significance excesses higher than two standard deviations for 304 sources, and the corresponding fraction of expected spurious associations is ∼20%. We selected hard X-ray blazars according to their significance level and carried out a statistical analysis to characterise their emission properties. A sample of 121 blazars detected at a significance level σ>3 is discussed in greater detail. The fraction of blazars with uncertain classification in this sample is considerable (∼23%), more than twice the percentage obtained considering all the blazars classified in the Roma-BZCAT (∼9%). We attribute the X-ray flux of the majority of selected BL Lac objects to the synchrotron emission.
galaxies: active - BL Lacertae objects: general - radiation mechanisms: non-thermal
VizieR on-line data:
<Available at CDS (J/A+A/520/A47): table2.dat>