V. Beckmann (1,2), A. Wolter (3), A. Celotti (4), L. Costamante (3), G. Ghisellini (3), T. Maccacaro (3), G. Tagliaferri (3)
(1) INTEGRAL Science Data Centre, Chemin d'Ecogia 16, CH-1290 Versoix, Switzerland
(2) Institut für Astronomie und Astrophysik, Astronomie, Universität
Tübingen, Sand 1, D-72076 Tübingen, Germany
(3) Osservatorio Astronomico di Brera, Via Brera 28, I-20121 Milano, Italy
(4) SISSA/ISAS, Via Beirut 2-4, I-34014 Trieste, Italy
To appear in: Astronomy & Astrophysics
Abstract. We present BeppoSAX LECS, MECS, and PDS spectra of eleven X-ray selected BL Lacertae objects. Combining these sources with the ones presented elsewhere we have a sample of 21 BL Lacs from the Einstein Medium Sensitivity and Einstein Slew Survey. The sample shows strong correlations of several physical parameters with the peak frequency of the synchrotron branch of the spectral energy distribution. In particular the peak frequency is correlated to the X-ray spectral shape: objects with the peak near to the X-ray band show harder and straighter X-ray spectra than those of the low energy peaked sources. This work shows that the recently proposed unification scenario for different types of blazars can hold also within the class of high frequency peaked BL Lac objects.Key words: BL Lacertae objects: general - X-rays: galaxies
Paper (182k gzip'ed Postscript including figures) (astro-ph/0112311)
[Home Page] [Preprints 2001] [Quick Reference] [Feedback]
| Impressum
Last modified 14 Nov 2002 |