Astrophysical: Quasars

  • Publication
    Through Thick and Thin—H I Absorption in Cosmological Simulations
    We investigate the column density distribution function of neutral hydrogen at redshift z = 3 using a cosmological simulation of galaxy formation from the...
  • Publication
    Time Delay in QSO 0957+561 From 1984-1999 Optical Data
    Photometric optical data of QSO 0957+561 covering the period 1984-1999 are analyzed to discern between the two values of the time delay (417 and 424 days)...
  • Publication
    Time Delay of QSO 0957+561 and Cosmological Implications
    We obtain the time delay between the arrival time of the A and B images of the QSO 0957+561. The results of applying two different methods (the discrete cross...
  • Publication
    Toward a clean sample of ultra-luminous X-ray sources
    Context: .Observational follow-up programmes for the characterization of ultra-luminous X-ray sources (ULXs) require the construction of clean samples of such...
  • Publication
    Toward measuring supermassive black hole masses with interferometric observations of the dust continuum
    This work focuses on active galactic nuclei (AGNs) and on the relation between the sizes of the hot dust continuum and the broad-line region (BLR). We find that...
  • Publication
    Towards an automatic classification of distortions as merging indicators in AGN host galaxies
    Does a merging event always precede AGN activity? In this starting PhD project, we will try to address this question by quantifying the distortions and...
  • Publication
    Tracing a high redshift cosmic web with quasar systems
    Context. To understand the formation, evolution, and present-day properties of the cosmic web we need to study it at low and high redshifts. Aims: We trace the...
  • Talk
    Triggering Quasars
    In the 50 years since their discovery, it has become increasingly recognised that quasars are not merely signposts to the distant Universe, but also play a key...
  • Publication
    Two emission line objects with z > 0.2 in the optical filament apparently connecting the Seyfert galaxy NGC 7603 to its companion
    We present new spectroscopic observations of an old case of anomalous redshift - NGC 7603 and its companion. The redshifts of the two galaxies which are...