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ASCA Large Sky Survey

Published by High Energy Astrophysics Science Archive Research Center | National Aeronautics and Space Administration | Metadata Last Checked: February 21, 2026 | Last Modified: 2026-02-17
The ASCA Large Sky Survey (LSS) was the first wide-area unbiased survey with the ASCA satellite in the 0.7 - 10 keV band around the North Galactic Pole region covering a continuous area of 7 square degrees. To make the best use of ASCA's capabilities, the authors developed a new source detection method in which the complicated detector responses were fully taken into account. Applying this method to the entire LSS data independently in the total (0.7 - 7 keV), hard (2 - 10 keV), and soft (0.7 - 2 keV) bands, they detected 107 sources altogether, with sensitivity limits of 6 x 10<sup>-14</sup> (0.7 - 7 keV), 1 x 10<sup>-13</sup> (2 - 10 keV), and 2 x 10<sup>-14</sup> ergs/s/cm<sup>2</sup> (0.7 - 2 keV), respectively. The complete list of detected sources is presented in this table. The detection criteria that needed to be satisfied were: (i) the significance of the summed count rate of the GIS and the SIS should exceed 4.5, and (ii) the significance of either the GIS or the SIS should also exceed 3.5. This database was created by the HEASARC in December 2001 based on the ADC/<a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/518/656">CDS Catalog J/ApJ/518/656</a>. This is a service provided by NASA HEASARC .

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