Astrophysical: Quasars

  • Publication
    A Population of Dust-rich Quasars at z ~ 1.5
    We report Herschel SPIRE (250, 350, and 500 μm) detections of 32 quasars with redshifts 0.5
  • Publication
    A possible binary AGN in Mrk 622?
    Mrk 622 is a Compton thick active galactic nuclei (AGN) and a double-peaked narrow emission line galaxy, thus a dual AGN candidate. In this work, new optical...
  • Publication
    A Possible Relationship between Quasars and Clusters of Galaxies
    The distribution on the sky of clusters of galaxies shows significant association with relatively nearby, large, active galaxies. The pattern is that of...
  • Publication
    A QSO Discovered at the Redshift of the Extended X-Ray Cluster RX J0152.7-1357
    The galaxy cluster RX J0152.7-1357 at z=0.8325 is one of the most luminous X-ray clusters known. It is elongated toward the bright, nearby, X-ray active galaxy...
  • Publication
    A quasar hiding behind two dusty absorbers. Quantifying the selection bias of metal-rich, damped Lyα absorption systems
    The cosmic chemical enrichment as measured from damped Lyα absorbers (DLAs) will be underestimated if dusty and metal-rich absorbers have evaded identification...
  • Publication
    A refined sub-grid model for black hole accretion and AGN feedback in large cosmological simulations
    In large-scale cosmological hydrodynamic simulations simplified sub-grid models for gas accretion on to black holes and AGN feedback are commonly used. Such...
  • Publication
    A Robust Determination of the Size of Quasar Accretion Disks Using Gravitational Microlensing
    Using microlensing measurements for a sample of 27 image pairs of 19 lensed quasars we determine a maximum likelihood estimate for the accretion disk size of an...
  • Publication
    A Study of Gravitational Lens Chromaticity Using Ground-based Narrowband Photometry
    We present observations of wavelength-dependent flux ratios for four gravitational lens systems (SDSS J1650+4251, HE 0435-1223, FBQ 0951+2635, and Q 0142-100)...
  • Publication
    A study of the 15-μm quasars in the ELAIS N1 and N2 fields
    This paper discusses the properties of the European Large Area ISO Survey (ELAIS) 15-μm quasars and tries to establish a robust method of quasar selection for...