Astrophysical: Quasars

  • Publication
    Detection of the 2175 Å Extinction Feature at z = 0.83
    We determine the extinction curve in the zl=0.83 lens galaxy of the gravitational lens SBS 0909+532 from the wavelength dependence of the flux ratio between the...
  • Publication
    Detection of very high energy gamma-ray emission from the gravitationally lensed blazar QSO B0218+357 with the MAGIC telescopes
    Context. QSO B0218+357 is a gravitationally lensed blazar located at a redshift of 0.944. The gravitational lensing splits the emitted radiation into two...
  • Publication
    Determination of the properties of the central engine in microlensed QSOs
    We study a recently observed gravitational microlensing peak in the V-band light curve of Q2237+0305A using a relatively simple physical model, but one that is...
  • Publication
    Determining the fraction of reddened quasars in COSMOS with multiple selection techniques from X-ray to radio wavelengths
    The sub-population of quasars reddened by intrinsic or intervening clouds of dust are known to be underrepresented in optical quasar surveys. By defining a...
  • Publication
    Discovery of a binary quasar at z = 1.76
    We present the serendipitous discovery of a physical pair of quasars with estimated cosmological redshift z = 1.76. Long-slit spectroscopic observations of the...
  • News
    Discovery of relativistic jets blowing bubbles in the central region of the Teacup Galaxy
    A study led by Anelise Audibert, a researcher at the Instituto de Astrofísica de Canarias (IAC), reveals a process that explains the peculiar morphology of the...
  • Publication
    Discovery of Very High Energy γ-Rays from 1ES 1011+496 at z = 0.212
    We report on the discovery of very high energy (VHE) γ-ray emission from the BL Lacertae object 1ES 1011+496. The observation was triggered by an optical...
  • Publication
    Do the Most Massive Black Holes at z = 2 Grow via Major Mergers?
    The most frequently proposed model for the origin of quasars holds that the high accretion rates seen in luminous active galactic nuclei (AGN) are primarily...
  • Publication
    Dramatic emission line variations in QSO KAZ 102 and possible causes
    We report optical spectroscopic observations of the radio-quiet quasar Kaz 102. We find impressive variations of the Hα emission line both in shape and...