Astrophysical: Quasars

  • Publication
    OJ 287 and the predicted fade of 1998
    There were predictions that blazar OJ 287 should have faded in late 1997 or early 1998. The observational background for these predictions is the sudden fade of...
  • Publication
    On the Connection of the Apparent Proper Motion and the VLBI Structure of Compact Radio Sources
    Many of the compact extragalactic radio sources that are used as fiducial points to define the celestial reference frame are known to have proper motions...
  • Publication
    On the lensed blazar B0218+357
    We present an optical spectrum (λλ4000-10 500) of the lensed blazar B0218+357 secured at the 10 m GTC and aimed to investigate and clarify the properties of...
  • Publication
    On the multiplicity of ALMA Compact Array counterparts of far-infrared bright quasars
    We present ALMA Atacama Compact Array (ACA) 870 μm continuum maps of 28 infrared-bright SDSS quasars with Herschel/SPIRE detections at redshifts 2-4, the...
  • Publication
    On the nature of the red, 2MASS-selected AGN in the local Universe I: an optical spectroscopic study
    We present optical spectra for a representative sample of 27 nearby (z 0.2) Two Micron All Sky Survey (2MASS)-selected active galactic nuclei (AGN) with red...
  • Publication
    On the optical counterparts of radio transients and variables
    We investigate the relation between the radio (Fr) and optical (Fo) flux densities of a variety of classes of radio transients and variables, with the aim of...
  • Publication
    On the optical variability of the QSO PKS 2128-123
    Although the QSO PKS 2128 - 123 appears as highly variable in the I band, with Delta-I of up to 1.69 mag, it is a moderate amplitude variable object in the...
  • Publication
    On the origin of the γ-ray emission from the flaring blazar PKS 1222+216
    The flat-spectrum radio quasar PKS 1222+216 (4C+21.35, z = 0.432) was detected in the very high energy γ-ray band by MAGIC during a highly active γ-ray phase...
  • Publication
    On the Redshift of TeV BL Lac Objects
    We report results of a spectroscopic campaign carried out at the 10 m Gran Telescopio Canarias for a sample of 22 BL Lac objects detected (or candidates) at TeV...