منابع مشابه
Structure and flux variability in the VLBI jet of BL Lacertae during the WEBT ⋆ campaigns ( 1995 – 2004 )
BL Lacertae has been the target of several observing campaigns by the Whole Earth Blazar Telescope (WEBT) collaboration and is one of the best studied blazars at all accessible wavelengths. A recent analysis of the optical and radio variability indicates that part of the radio variability is correlated with the optical light curve. Here we present an analysis of a huge VLBI data set including 1...
متن کاملThe correlated optical and radio variability of BL Lacertae WEBT data analysis 1994 – 2005 ⋆
Context. Since 1997, BL Lacertae has undergone a phase of high optical activity, with the occurrence of several prominent outbursts. Starting from 1999, the Whole Earth Blazar Telescope (WEBT) consortium has organized various multifrequency campaigns on this blazar, collecting tens of thousands of data points. One of the main issues in the study of this huge dataset has been the search for corr...
متن کاملWEBT multiwavelength monitoring and XMM-Newton observations of BL Lacertae in 2007–2008 Unveiling different emission components
Context. BL Lacertae is the prototype of the blazar subclass named after it. Yet, it has occasionally shown a peculiar behaviour that has questioned a simple interpretation of its broad-band emission in terms of synchrotron plus synchrotron self-Compton (SSC) radiation. Aims. In the 2007–2008 observing season we carried out a new multiwavelength campaign of the Whole Earth Blazar Telescope (WEB...
متن کاملThe Cosmological Evolution of BL Lacertae Objects
We review the main results from several radio, X-ray and multi-frequency surveys on the topic of cosmological evolution of BL Lacertae objects. Updated findings on BL Lac evolution following the recent identification of many sources in the ”Sedentary Multi-Frequency survey” are also discussed. By means of extensive Monte Carlo simulations we test some possible explanations for the peculiar cosm...
متن کاملOn the relationship between BL Lacertae objects and radio galaxies
We present deep radio images at 1.4 GHz of a large and complete sample of BL Lacertae objects (BL Lacs) selected from the Deep X-ray Radio Blazar Survey (DXRBS). We have observed 24 northern (δ ∼ −30 ◦) sources with the Very Large Array (VLA) in both its A and C configurations and 15 southern sources with the Australia Telescope Compact Array (ATCA) in its largest configuration. We find that in...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2004
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20040439