Astrophysical: Quasars

  • Publication
    Star formation rates in luminous quasars at 2 < z < 3
    We investigate the relation between star formation rates (dot{{M}}_s) and AGN properties in optically selected type 1 quasars at 2 z 3 using data from...
  • Publication
    Stars and brown dwarfs in the σ Orionis cluster. III. OSIRIS/GTC low-resolution spectroscopy of variable sources
    Context. Although many studies have been performed so far, there are still dozens of low-mass stars and brown dwarfs in the young σ Orionis open cluster without...
  • Publication
    Statistics of Microlensing Caustic Crossings in Q 2237+0305: Peculiar Velocity of the Lens Galaxy and Accretion Disk Size
    We use the statistics of caustic crossings induced by microlensing in the lens system Q 2237+0305 to study the lens galaxy peculiar velocity. We calculate the...
  • Talk
    Stellar dynamics at the centers of galaxies
    The massive black holes found at the centers of most nearby galaxies including our own, are believed to be the ashes of the fuel that powered quasars early in...
  • Publication
    Stellar mass fraction and quasar accretion disk size in SDSS J1004+4112 from photometric follow-up
    The gravitational lens SDSS J1004+4112 was the first discovered system where a background quasar is lensed by a galaxy cluster instead of a single galaxy. We...
  • Publication
    STRIDES: automated uniform models for 30 quadruply imaged quasars
    Gravitational time delays provide a powerful one-step measurement of H 0, independent of all other probes. One key ingredient in time-delay cosmography are high...
  • Publication
    Strong Chromatic Microlensing in HE0047–1756 and SDSS1155+6346
    We use spectra of the double-lensed quasars HE0047–1756 and SDSS1155+6346 to study their unresolved structure through the impact of microlensing. There is no...
  • Publication
    Strong lensing reveals jets in a sub-microJy radio-quiet quasar
    We present e-MERLIN and European VLBI Network observations which reveal unambiguous jet activity within radio-quiet quasar HS 0810+2554. With an intrinsic flux...
  • Publication
    Structure of the Accretion Disk in the Lensed Quasar Q2237+0305 from Multi-epoch and Multi-wavelength Narrowband Photometry
    We present estimates for the size and the logarithmic slope of the disk temperature profile of the lensed quasar Q2237+0305, independent of the component...