Astrophysical: BL Lacertae objects

  • Publication
    The Hubble Space Telescope Survey of BL Lacertae Objects. III. Morphological Properties of Low-Redshift Host Galaxies
    We report on the optical properties of a sample of 30 BL Lac host galaxies in the redshift range 0.03
  • Publication
    The Hubble Space Telescope Survey of BL Lacertae Objects. IV. Infrared Imaging of Host Galaxies
    The Hubble Space Telescope NICMOS Camera 2 was used for H-band imaging of 12 BL Lacertae objects taken from the larger sample observed with the WFPC2 in the R...
  • Publication
    The Hubble Space Telescope Survey of BL Lacertae Objects: Gravitational Lens Candidates and Other Unusual Sources
    We present Hubble Space Telescope (HST) observations of seven unusual objects from the HST ``snapshot survey'' of BL Lacertae objects, of which four are...
  • Publication
    The I.A.C./Q.M.C. catalogue of quasar multiband spectra.
    One of the major problems using quasars to investigate the Hubble diagram is an uncertainty as to the size of the bolometric correction. Some estimates have...
  • Publication
    The June 2008 Flare of Markarian 421 from Optical to TeV Energies
    We present optical, X-ray, high-energy (lap30 GeV) and very high energy (gap100 GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between...
  • Publication
    The Nature of Close Companions of the BL Lacertae Objects 1ES 0502+675 and 1ES 1440+122
    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...
  • Publication
    The 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...
  • Publication
    The 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...
  • Publication
    The 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...