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The Rosat X-Ray Spectra of BL Lacertae Objects

Published online by Cambridge University Press:  25 May 2016

Paolo Padovani
Affiliation:
Dipartimento di Fisica, II Università di Roma “Tor Vergata” Via della Ricerca Scientifica 1, I-00133 Roma, Italy SAX, Scientific Data Center, ASI Viale Regina Margherita 202, I-00198 Roma, Italy
Paolo Giommi
Affiliation:
Dipartimento di Fisica, II Università di Roma “Tor Vergata” Via della Ricerca Scientifica 1, I-00133 Roma, Italy SAX, Scientific Data Center, ASI Viale Regina Margherita 202, I-00198 Roma, Italy

Extract

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We have analyzed the X-ray spectra of all BL Lacs observed (as pointed or serendipitous sources) by ROSAT. Spectral indices were obtained from the hardness ratios given in the WGA catalogue, a large list of X-ray sources generated from all the ROSAT PSPC pointed observations. The selection of the objects was done by cross-correlating the first revision of the WGA catalogue with our recent catalogue of BL Lacs. This resulted in 163 observations of 85 distinct BL Lacs, which correspond to about half the confirmed BL Lacs presently known. This represents the largest number of BL Lacs for which homogeneous X-ray spectral information is available and the largest BL Lac sample ever studied at X-ray frequencies.

Type
Relation between Radio and Other Wavelenghts
Copyright
Copyright © Kluwer 1996 

References

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