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The 0.1-200 keV spectrum of the blazar PKS 2005-489 during an active state
G. Tagliaferri, G. Ghisellini, P. Giommi +8
The bright BL Lac object PKS 2005-489 was observed by BeppoSAX on November 1-2, 1998, following an active X-ray state detected by RossiXTE. The source, detected between 0.1 and 200…
The X-Ray Jet of PKS 0637-752: Inverse Compton Radiation from the Cosmic Microwave Background ?
F. Tavecchio, L. Maraschi R. M. Sambruna, C. M. Urry
We propose that the X-ray emission detected by Chandra from the 100-kiloparsec-scale jet of PKS 0637-752 is produced through inverse Compton scattering of the Cosmic Microwave Back…
BeppoSAX Observations of Markarian 501 in June 1999
E. Pian, L. Chiappetti, P. Giommi +19
We present the preliminary results of a long BeppoSAX observation of the BL Lac object Mkn501 carried out in June 1999. The source was fainter than found during the BeppoSAX pointi…
Two BeppoSAX observations of BL Lac
G. Tagliaferri, G. Ghisellini, M. Ravasio +14
We present the results of two ToO BeppoSAX observations of BL Lac. During the first observation we detected both the synchrotron and the Compton components. Fast time variability w…
Hard synchrotron BL Lacs: the case of 1ES 1101-232
Anna Wolter, Gabriele Ghisellini, Gianpiero Tagliaferri +2
The bright X-ray selected BL Lac object 1ES1101--232 shows a flat X-ray spectrum, making it detectable with high statistics over the wide BeppoSAX energy range. We have observed it…
Looking for High Energy Peaked Blazars
L. Costamante, G. Ghisellini, A. Celotti +10
Blazars can be classified on the basis of their overall Spectral Energy Distribution (SED). BL Lac objects are usually divided in LBL or HBL (Low or High energy peaked BL Lacs), ac…
X-ray Emission of Mkn 421: New Clues From Its Spectral Evolution. II. Spectral Analysis and Physical Constraints
G. Fossati, A. Celotti, M. Chiaberge +7
Mkn 421 was repeatedly observed with BeppoSAX in 1997-1998. The source showed a very rich phenomenology, with remarkable spectral variability. This is the second of two papers pres…
X-ray Emission of Mkn 421: New Clues From Its Spectral Evolution. I. Temporal Analysis
G. Fossati, A. Celotti, M. Chiaberge +7
Mkn 421 was repeatedly observed with BeppoSAX in 1997-1998. This is the first of two papers where we present the results of a thorough temporal and spectral analysis of all the dat…
Gamma-loud quasars: a view with BeppoSAX
F. Tavecchio, L. Maraschi, G. Ghisellini +12
We present SAX observations of the -ray emitting quasars 0836+710, 1510-089 and 2230+114. All the objects have been detected in the PDS up to 100 keV and have extremely f…
Constraints to the SSC model for Mkn 501
Fabrizio Tavecchio, Laura Maraschi Osservatorio Astronomico di Brera, Milano +1
We fit the SEDs of the TeV blazar Mkn 501 adopting the homogeneous Synchrotron-Self Compton model to simultaneous X-ray and TeV spectra recently become available. We present detail…
X-ray variability and prediction of TeV emission in the HBL 1ES1101-232
A. Wolter, F. Tavecchio, A. Caccianiga +2
1ES1101-232 is a bright BL Lac of the High frequency peak class. We present here the results of two BeppoSAX observations in which the source has shown a variation of about 30% in…
New Extreme Synchrotron BL Lac Objects
L. Costamante, G. Ghisellini, P. Giommi +10
We report on the BeppoSAX observations of four "extreme" BL Lacs, selected to have high synchrotron peak frequencies. All have been detected also in the PDS band. For 1ES 0120+340,…