1998/10/09 by V. Beckmann, Volker Beckmann, Beckmann, Volker
Engineering · Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #Particle Accelerators and Free-Electron Lasers #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9810154
12 pages, 6 Postscript figures, to appear in the proceedings of the conference "BL Lac Phenomenon" held in Turku, Finland, June 22-26, 1998
arxiv created 1998/10/09 · openalex publication_date 1998/10/09 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present analysis of a new flux limited sample of 72 X-ray selected BL Lacertae objects with known redshifts for 59 of them. We find the more X-ray dominated BL Lac having negative evolution with redshift, while intermediate objects show no evolution at all. X-ray dominated objects show higher X-ray luminosities and flatter X-ray spectra than the intermediate ones. We were also able to determine the redshift of 1517+656, which is part of our sample and is the optically most luminous X-ray selected BL Lac known so far.