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Demographics of Blazars
G. Fossati
We discuss the preliminary results of an extensive effort to address the fundamental, and yet un-answered, question that can be trivialized as: ``are there more blue or red blazars…
Complex Spectral Variability from Intensive Multi-wavelength Monitoring of Mrk421 in 1998
T. Takahashi, J. Kataoka, G. Madejski +20
We conducted a multi-frequency campaign for the TeV blazar Mrk~421 in 1998 April. The campaign started from a pronounced high amplitude flare recorded by SAX and Whipple; ASCA obse…
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…
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…
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,…