Optical and radio data from the 1989 minimum are analyzed to examine the implications of the light curves for the spectrum. The optical spectrum increases...
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PublicationA turned-over optical spectrum of OJ287 during the 1989 minimum
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PublicationAn intermittent extreme BL Lac: MWL study of 1ES 2344+514 in an enhanced state
Extreme high-frequency BL Lacs (EHBL) feature their synchrotron peak of the broad-band spectral energy distribution (SED) at νs ≥ 1017 Hz. The BL Lac object 1ES...
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PublicationAn interpretation of the lightcurve of BL Lac.
Extensive monitoring is now available for a good sample of the brighter quasars and BL Lacs. In some cases, lightcurves are well enough sampled to permit...
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PublicationAre high polarization quasars and BL Lacertae objects really different? A study of the optical spectral properties.
The continuum and emission lines properties of a sample of 73 blazars is studied, investigating differences and similarities among normal low-polarization...
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NewsAstronomers discover rapid oscillations in the light of a blazar
The international collaboration Whole Earth Blazar Telescope (WEBT), in which researchers from the Instituto de Astrofísica de Canarias (IAC) participate, has...
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PublicationBL Lac nuclei in elliptical galaxies
Orientation effects are believed to be important in sources which harbor relativistic jets in their nuclei. BL Lac type objects are interpreted as a type of...
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PublicationBroad-band continuum and line emission of the gamma-ray blazar PKS 0537-441
PKS 0537-441, a bright gamma -ray emitting blazar, was observed at radio, optical, UV and X-ray frequencies during various EGRET pointings, often quasi...
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PublicationBroadband characterisation of the very intense TeV flares of the blazar 1ES 1959+650 in 2016
1ES 1959+650 is a bright TeV high-frequency-peaked BL Lac object exhibiting interesting features like "orphan" TeV flares and broad emission in the high-energy...
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PublicationCCD monitoring of quasars and BL Lacertae objects
Johnson B CCD photometry of quasars and other active nuclei were obtained with the 1-m and 2.5-m reflectors of the Roque de los Muchachos Observatory in the...