Astrophysical: Accretion

  • Publication
    A refined dynamical mass for the black hole in the X-ray transient XTE J1859+226
    We present two contiguous nights of simultaneous time-resolved Gran Telescopio Canarias spectroscopy and William Herschel Telescope photometry of the black hole...
  • Publication
    A return to strong radio flaring by Circinus X-1 observed with the Karoo Array Telescope test array KAT-7
    Circinus X-1 is a bright and highly variable X-ray binary which displays strong and rapid evolution in all wavebands. Radio flaring, associated with the...
  • 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 search for evidence of irradiation in Centaurus X-4 during quiescence
    Aims.We present a study of the neutron star X-Ray Transient Cen X-4. Our aim is to look for any evidence of irradiation of the companion with a detailed...
  • Publication
    A signature of the donor star in the extra-galactic X-ray binary LMCX-2
    Two nights of phase-resolved medium-resolution Very Large Telescope spectroscopy of the extra-galactic low-mass X-ray binary LMCX-2 have revealed a 0.32 +/- 0...
  • Publication
    A Strongly Heated Neutron Star in the Transient Z Source MAXI J0556-332
    We present Chandra, XMM-Newton, and Swift observations of the quiescent neutron star in the transient low-mass X-ray binary MAXI J0556-332. Observations of the...
  • 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)...
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    A Study of Gravitational Lens Chromaticity with the Hubble Space Telescope
    We report Hubble Space Telescope observations of six gravitational lenses with the Advanced Camera for Surveys. We measured the flux ratios between the lensed...
  • Publication
    A TiO study of the black hole binary GRO J0422+32 in a very low state
    We present 53 simultaneous photometric (I band) and spectroscopic (6900-9500Å) observations of GRO J0422+32, taken during 1997 December. From these we determine...