TY - JOUR
T1 - The blazar content in the Swift -BAT hard X-ray sky
AU - Maselli, A.
AU - Cusumano, G.
AU - Massaro, E.
AU - La Parola, V.
AU - Segreto, A.
AU - Sbarufatti, B.
PY - 2010/9/30
Y1 - 2010/9/30
N2 - Aims. We present the results from a study of the blazar content in the 15-150 keV map of the entire sky obtained analysing 39 months of data collected by the BAT telescope aboard the Swift satellite. Methods. 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. Results. 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.
AB - Aims. We present the results from a study of the blazar content in the 15-150 keV map of the entire sky obtained analysing 39 months of data collected by the BAT telescope aboard the Swift satellite. Methods. 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. Results. 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.
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U2 - 10.1051/0004-6361/201014331
DO - 10.1051/0004-6361/201014331
M3 - Article
AN - SCOPUS:77957565551
SN - 0004-6361
VL - 520
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
IS - 6
M1 - A47
ER -