We report on long-term multiwavelength monitoring of blazar Mrk 421 by the GLAST-AGILE Support Program of the Whole Earth Blazar Telescope (GASP-WEBT)...
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PublicationDissecting the long-term emission behaviour of the BL Lac object Mrk 421
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PublicationDo all bright elliptical galaxies have active nuclei?
The evidence is noted that (1) a flux density limited complete sample of X-ray emitting BL Lac type sources is now available from Schwartz and Ku (1983), that...
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PublicationElectron-beam interaction with emission-line clouds in blazars
Context. An electron-positron beam escaping from the magnetospheric vacuum gap of an accreting black hole interacts with recombination-line photons from...
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PublicationESO Very Large Telescope Optical Spectroscopy of BL Lacertae Objects. I. New Redshifts
We report redshift measurements for 12 BL Lacertae objects from a program aimed at obtaining high signal-to-noise ratio (up to ~500) optical spectroscopy of a...
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PublicationESO Very Large Telescope Optical Spectroscopy of BL Lacertae Objects. II. New Redshifts, Featureless Objects, and Classification Assessments
We report on ESO Very Large Telescope optical spectroscopy of 42 BL Lacertae objects of unknown redshift. Nuclear emission lines were observed in 12 objects...
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PublicationExtreme HBL behavior of Markarian 501 during 2012
Aims: We aim to characterize the multiwavelength emission from Markarian 501 (Mrk 501), quantify the energy-dependent variability, study the potential multiband...
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PublicationExtreme photometric and polarimetric variability of blazar S4 0954+65 at its maximum optical and γ-ray brightness levels
In 2022 the BL Lac object S4 0954+65 underwent a major variability phase, reaching its historical maximum brightness in the optical and γ-ray bands. We present...
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PublicationFermi Large Area Telescope Observations of Markarian 421: The Missing Piece of its Spectral Energy Distribution
We report on the γ-ray activity of the high-synchrotron-peaked BL Lacertae object Markarian 421 (Mrk 421) during the first 1.5 years of Fermi operation, from...
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PublicationFirst broadband characterization and redshift determination of the VHE blazar MAGIC J2001+439
Aims: We aim to characterize the broadband emission from 2FGL J2001.1+4352, which has been associated with the unknown-redshift blazar MG4 J200112+4352. Based...