Astrophysical: BL Lacertae objects

  • Publication
    Disentangling the nature of the prototype radio weak BL Lac. Contemporaneous multifrequency observations of WISE J141046.00+740511.2
    Context. The γ-ray emitting source WISE J141046.00+740511.2 has been associated with a Fermi-LAT detection by crossmatching with Swift/XRT data. It has shown...
  • Publication
    Dissecting the long-term emission behaviour of the BL Lac object Mrk 421
    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)...
  • Publication
    Distance estimation of gamma-ray-emitting BL Lac objects from imaging observations
    Aims. The direct redshift determination of BL Lac objects is highly challenging as the emission in the optical and near-infrared bands is largely dominated by...
  • Publication
    Do 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...
  • Publication
    Electron-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...
  • Publication
    ESO 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...
  • Publication
    ESO 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...
  • Publication
    Extreme 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...
  • Publication
    Extreme 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...