TIME-RESOLVED ULTRAVIOLET SPECTROSCOPY OF THE CATACLYSMIC VARIABLE, PG-1711+336.
MON NOT R ASTRON SOC
40 - 47.
Low-resolution IUE ultraviolet observations of the cataclysmic variable, PG 1711+336, are presented. The spectra reveal extensive variability in the wind-formed C IV lambda-1550 resonance line P Cygni profiles, on time-scales as short as approximately hours. We demonstrate that the high-resolution IUE spectrum of the nova-like system V3885 Sgr, convolved with the IUE low-resolution instrumental profile, provides a good match to the low-resolution wind lines of PG 1711+336 at some epochs. Hot-star wind theory and spherical symmetry are assumed in order to model the high-resolution data. The results yield a crude time-independent (lower-limit) estimate for the product of mass-loss rate and ion fraction. Moments of the observed P Cygni profiles in PG 1711+336 are measured to quantify the wind variability, and suggest that the C IV wind column densities may vary by a factor of approximately 2 in approximately 1 hour. We estimate changes of a factor of approximately 2 in the edge velocities of the shortward-shifted resonance lines, with maximum values of approximately 4500 kms-1.The stellar-wind variability is not accompanied by any significant changes in the continuum flux level or distribution over approximately 1150-3200 angstrom. The mean UV continuum may be fitted by a power law of the form f-lambda-proportional-lambda approximately (-2.0+/-0.1). These limited data do not suggest a simple correlation between the wind variability and the orbital phase of PG 1711+336.
|Title:||TIME-RESOLVED ULTRAVIOLET SPECTROSCOPY OF THE CATACLYSMIC VARIABLE, PG-1711+336|
|Keywords:||RESONANCE LINES, DWARF NOVA, WINDS, PHASE, ATMOSPHERES, SPECTRA, MAJORIS, STARS, UV|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Physics and Astronomy|
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