Search Publications
An X-ray, optical and radio study of PKS 0745-191 : a massive coolingflow.
McHardy, I.; Fabian, A. C.; Elvis, M. +7 more
The X-ray source 3A 0745-191 is identified with intracluster gas surrounding the giant galaxy containing the radio source, PKS 0745-191, which lies at z = 0.1. The gas is cooling at the unprecedented rate of 1000 M_sun;yr-1. Optical line-emitting gas extends more than 10 kpc from the centre of the galaxy and corroborates the high mass-f…
Investigation of a wind model for cataclysmic variable ultraviolet resonance line emission.
Verbunt, F.; Drew, J.
The present investigation of ionization and thermal structure in a spherically symmetric, radiatively driven wind emanating from the vicinity of a cataclysmic variable's white dwarf notes that wind ionization is always high for plausible wind and radiation field parameter values, and that resonance scattering dominates line formation at large radi…
EXOSAT soft X-ray observations of EX Hydrae.
Kahn, S. M.; Mason, K. O.; Cordova, F. A.
During a continuous 26 hour X-ray observation of the 98-min binary EX Hydrae using the CMA detector on EXOSAT, a 67-min modulation was detected with a pulse-fraction of about 30 per cent. The phase of the modulation coincides with that of the 67-min optical modulation which has a pulse-fraction of 15 per cent. The X-ray and optical pulse shapes ar…
IUE observations of HD 36705.
Rucinski, S. M.
HD 36705 is one of the most rapidly rotating (0.514-day) possibly single late-type (K0/2) stars known. The IUE was used to obtain ten LWR high resolution and five SWP low-resolution spectra in different phases of the rotational period. The FES light curve indicates a rather uniform coverage by spots during the observations. The Mg II emission line…
On the ultraviolet spectrum of AG Peg.
Penston, M. V.; Allen, D. A.
AG Peg has displayed the slowest known nova outburst. Since the system contains an M giant, it can be classified as symbiotic star. Presented are ultraviolet spectra of AG Peg taken with the IUE satellite. A variety of regimes having characteristically different spectral features is found. These include a high-velocity wind in which high-ionizatio…
Dwarf novae in outburst : monitoring WX Hydri with IUE.
Verbunt, F.; Pringle, J. E.; Hassall, B. J. M.
An account is given of the monitoring of WX Hydri with the International Ultraviolet Explorer (IUE) satellite. The data obtained at the beginning of an outburst show that the rise of the optical precedes that of the ultraviolet flux. Observations during quiescence, together with archival data, indicate that the ultraviolet continuum and line fluxe…
EXOSAT MEDA observations of Cygnus X-3.
King, A. R.; Pounds, K. A.; Willingale, R.
Results of a continuous 30.6-hr X-ray observation of Cygnus X-3 with a large area detector are presented. These show the well known, roughly sinusoidal light curve at the 4.8-hr period, with a phase-dependent variability at short time-scales, and associated spectral behavior. The sinusoidal modulation is interpreted as due to electron scattering i…
A superoutburst of the dwarf nova EK Trianguli Australis.
Hassall, B. J. M.
Simultaneous UV and optical spectrophotometry were obtained during several stages of a superoutburst of EK TrA. The observed spectra are compared with steady disc models, built both of blackbodies or Kurucz stellar atmospheres and with optically thin contributions. Atmosphere models predict much lower mass transfer rates than blackbody models. Ass…
Simultaneous X-ray and optical observations of the X-ray dip source X1755-338.
Parmar, A. N.; White, N. E.; Mason, K. O.
Simultaneous X-ray and optical observations have been made of the 'dipping' X-ray source X1755-338 which has a dip recurrence period of 4.4 hr. A sinusoidal modulation of amplitude 0.4 mag is found in the V-band light of the 18 mag optical counterpart of the X-ray source. The period of the optical modulation is consistent with the X-ray dip recurr…
Condensation of dust around the WC7 star HD 192641 (WR 137).
Telesco, C. M.; van der Hucht, K. A.; Longmore, A. J. +4 more
The WC7+ absorption class Wolf-Rayet star WR 137 (=HD 192641) is shown to have brightened significantly in the infrared since 1978, most rapidly between 1983 and mid-1984. This is ascribed to an increase in the mass loss rate and the condensation of dust grains in the stellar wind. At maximum, the dust mass was about 10-8 Msun