We report on deep radio images and optical spectroscopy of two BL Lac objects that have very close compact companions. The two targets, 1ES 0502+675 and 1ES...
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PublicaciónThe Nature of Close Companions of the BL Lacertae Objects 1ES 0502+675 and 1ES 1440+122
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PublicaciónThe near-infrared-optical-ultraviolet emission of BL Lacertae objects
Near-infrared, optical, and ultraviolet quasi-simultaneous observations of 11 BL Lacertae objects are reported. For all but one source the dereddened spectral...
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PublicaciónThe optical behaviour of BL Lacertae at its maximum brightness levels: a blend of geometry and energetics
In 2021 BL Lacertae underwent an extraordinary activity phase, which was intensively followed by the Whole Earth Blazar Telescope (WEBT) Collaboration. We...
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PublicaciónThe Redshift of the BL Lac Object TXS 0506+056
The bright BL Lac object TXS 0506+056 is the most likely counterpart of the IceCube neutrino event EHE 170922A. The lack of this redshift prevents a...
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PublicaciónThe relation between optical and γ-ray emission in BL Lac sources
The relativistic jets produced by some Active Galactic Nuclei (AGNs) are among the most efficient persistent sources of non-thermal radiation and represent an...
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PublicaciónThe simultaneous low state spectral energy distribution of 1ES 2344+514 from radio to very high energies
Context. BL Lacertae objects are variable at all energy bands on time scales down to minutes. To construct and interpret their spectral energy distribution (SED...
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PublicaciónThe spectra of IceCube Neutrino (SIN) candidate sources - III. Optical spectroscopy and source characterization of the full sample
A correlation between astrophysical high-energy neutrinos and blazars has been suggested by various authors. In particular, a likely association between IceCube...
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PublicaciónThe spectra of IceCube neutrino candidate sources - I. Optical spectroscopy of blazars
There is mounting evidence that ultra-energetic neutrinos of astrophysical origin may be associated with blazars. Here, we investigate a unique sample of 47...
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PublicaciónThe UV - optical - near-IR emission of BL Lacertae objects.
Results from UV, optical and near-IR simultaneous observations for 11 BL Lac objects are reported. The authors find that for all but one source the spectral...