Optical and radio properties of X-ray selected BL Lacertae objects

Abstract

view Abstract Citations (147) References (31) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Optical and radio properties of X-ray selected BL Lacertae objects. Stocke, J. T. ; Liebert, J. ; Schmidt, G. ; Gioia, I. M. ; Maccacaro, T. ; Schild, R. E. ; Maccagni, D. ; Arp, H. C. Abstract The eight BL Lac objects from the HEAO 1 A-2 all-sky survey and from the Einstein medium-sensitivity survey (MSS) form a flux-limited complete X-ray selected sample. The optical and radio properties of the MSS BL Lac objects are presented and compared with those of the HEAO 1 A-2 sample and with those of radio-selected BL Lac objects. The X-ray selected BL Lac objects possess smaller polarized fractions and less violent optical variability than radio-selected BL Lac objects. These properties are consistent with the substantial starlight fraction seen in the optical spectra of a majority of these objects. This starlight allows a determination of definite redshifts for two of four MSS BL Lac objects and a probable redshift for a third. These redshifts are 0.2, 0.3, and 0.6. Despite the differences in characteristics between the X-ray selected and radio-selected samples, it is concluded that these eight objects possess most of the basic qualities of BL Lac objects and should be considered members of that class. Moreover, as a class, these X-ray selected objects have the largest ratio of X-ray to optical flux of any active galactic nuclei yet discovered. Publication: The Astrophysical Journal Pub Date: November 1985 DOI: 10.1086/163646 Bibcode: 1985ApJ...298..619S Keywords: Bl Lacertae Objects; Galactic Nuclei; X Ray Sources; Active Galactic Nuclei; Astronomical Photometry; Galactic Clusters; Heao 1; Polarimetry; Radio Astronomy; Sky Surveys (Astronomy); Visible Spectrum; Astrophysics full text sources ADS | data products SIMBAD (20) NED (8)