Two New Bl-Lacertae Objects Discovered in the Error Boxes of Hard X-Ray Sources
Abstract
Two new BL Lacertae objects, located within the error boxes of hard X-ray sources, have been discovered during a systematic program to identify a large sample of EXOSAT serendipitous sources. Both hard X-ray sources were detected during the HEAD 1 whole sky survey and have been associated to a Seyfert galaxy and to a Be star. The EXOSAT data are consistent with the two BL Lacs being the only counterparts of the hard X-ray sources. If this is the case the space density of BL Lacs, at fluxes 3 x 10-11 erg cm -2 s -1 (2-10 keV), might be higher than previously thought. The implications for the shape on the X-ray LogN-LogS of BL Lac objects are briefly discussed.
- Publication:
-
BL Lac Objects
- Pub Date:
- 1989
- DOI:
- 10.1007/BFb0031170
- Bibcode:
- 1989LNP...334..257T