2003/11/04 by P. Padovani, L. Costamante, P. Giommi +3
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Earth Systems and Cosmic Evolution #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2004.07313.x
published as Mon.Not.Roy.Astron.Soc. 347 (2004) 1282 · 13 pages, 6 figures. Accepted for publication in MNRAS. Postscript file also available at http://www.stsci.edu/~padovani/xrayspectra_papers.html
arxiv created 2003/11/04 · openalex publication_date 2004/01/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present new BeppoSAX LECS and MECS observations, covering the energy range 0.1–10 keV (observer's frame), of four BL Lacertae objects selected from the 1-Jy sample. All sources display a flat (αx∼ 0.7) X-ray spectrum, which we interpret as inverse Compton emission. One object shows evidence for a low-energy steepening (Δαx∼ 0.9), which is probably due to the synchrotron component merging into the inverse Compton one around ∼2 keV. A variable synchrotron tail would explain why the ROSAT spectra of our sources are typically steeper than the BeppoSAX ones (Δαx∼ 0.7). The broad-band spectral energy distributions fully confirm this picture, and model fits using a synchrotron inverse Compton model allow us to derive the physical parameters (intrinsic power, magnetic field, etc.) of our sources. By combining the results of this paper with those previously obtained on other sources, we present a detailed study of the BeppoSAX properties of a well-defined subsample of 14 X-ray bright [ƒx(0.1–10) keV > 3 × 10−12 erg cm−2 s−1] 1-Jy BL Lacs. We find a very tight proportionality between nearly simultaneous radio and X-ray powers for the 1-Jy sources in which the X-ray band is dominated by inverse Compton emission, which points to a strong link between X-ray and radio emission components in these objects.