We present the first results of a program to identify the unknown bright active galactic nuclei (AGN) in the ROSAT All Sky Survey Bright Source Catalog (RASSBSC). We have used lg C+04 R as an alternative expression fo...We present the first results of a program to identify the unknown bright active galactic nuclei (AGN) in the ROSAT All Sky Survey Bright Source Catalog (RASSBSC). We have used lg C+04 R as an alternative expression for lg (f x f opt ), where C is X-ray count rate and R stands for R magnitude. Then a high X-ray-to-optical flux ratio criterion has been used to select an AGN sample with 165 unidentified X-ray sources for optical spectroscopy. At present over 93% of the X-ray sources in the sample have been fully identified in the following classes: emission line AGNs, clusters of galaxies, BL Lacertae objects, and stars.展开更多
文摘We present the first results of a program to identify the unknown bright active galactic nuclei (AGN) in the ROSAT All Sky Survey Bright Source Catalog (RASSBSC). We have used lg C+04 R as an alternative expression for lg (f x f opt ), where C is X-ray count rate and R stands for R magnitude. Then a high X-ray-to-optical flux ratio criterion has been used to select an AGN sample with 165 unidentified X-ray sources for optical spectroscopy. At present over 93% of the X-ray sources in the sample have been fully identified in the following classes: emission line AGNs, clusters of galaxies, BL Lacertae objects, and stars.
