Sky surveys with <i>ASCA</i> — Large Sky Survey

Abstract

Abstract We have carried out the first systematic wide‐area survey around a Galactic pole region with the ASCA satellite in the 0.7–10 keV energy band (Large Sky Survey; LSS). The observed area amounts to 7 deg 2 . To make the best use of ASCA capability, we have developed a new source‐detection method where the complicated detector responses are fully taken into account. Applying this method to the entire LSS data independently in three energy bands (0.7–2 keV, 2–10 keV, and 0.7‐7 keV), we detected 104 sources in total (4.5 σ detection). The Log N ‐ Log S relation and spectral properties of faint sources are presented.