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The broad band X-ray spectra of intermediate BL Lac objects

J. Siebert·W. Brinkmann·S. A. Laurent-Muehleisen·M. Matsuoka
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Abstract

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 alpha_rx. 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.

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J. Siebert, W. Brinkmann, S. A. Laurent-Muehleisen, M. Matsuoka. 1998-08-21. The broad band X-ray spectra of intermediate BL Lac objects. https://arxiv.org/abs/astro-ph/9808231

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