1998/08/21 by J. Siebert, Siebert, J., W. Brinkmann +6
Engineering · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #Particle Accelerators and Free-Electron Lasers #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9808231
4 pages, incl. 6 figures, to appear in the proceedings of the 32nd COSPAR Scientific Assembly, Section E1.1, Nagoya, Japan, July 13-15 1998, Adv. in Space Research
arxiv created 1998/08/21 · openalex publication_date 1998/08/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present recent X-ray observations of intermediate BL Lac objects (IBLs), i.e. BL Lacs which are located between high-energy and low-energy peaked BL Lac objects with respect to alpharx. We briefly discuss the statistical properties of IBLs from the RGB sample and then focus on a detailed broad band spectral analysis of two objects, namely 1424+2401 and 1055+5644, which were observed with ASCA and SAX, respectively. In both cases the spectra are steep and we find significant curvature in 1424+2401 in the sense that the spectrum gets flatter at both low (< 1 keV) and high energies (> 5 keV). Our results are in line with the hypothesis of a continuous distribution of synchrotron peak frequencies among BL Lac objects.