Time Variability in the Ultraviolet Resonance Lines of the Cataclysmic Variables Mu-Centauri Ah-Herculis and Qu-Carinae

Details Time Variability in the Ultraviolet Resonance Lines of the Cataclysmic Variables Mu-Centauri Ah-Herculis and Qu-Carinae Time Variability in the Ultraviolet Resonance Lines of the Cataclysmic Variables Mu-Centauri Ah-Herculis and Qu-Carinae

Aug 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994mnras.269..891k&link_type=abstract

Monthly Notices of the Royal Astronomical Society, Vol. 269, NO. 4/AUG15, P. 891, 1994

Astronomy and Astrophysics

Astronomy

14

Scientific paper

We present a time-variability study of the uV resonance lines Nv 1240, Si iv 1397 and C iv 1549 in the dwarf novae AH Her and MU Cen and the nova-like variable QU Car. The main findings are as follows. (i)Virtually no variation can be seen in our data for MU Cen. (ii) AH Her shows velocity shifting of its resonance lines, with semi-amplitudes ranging from approximately 500 to 800 km s1. Since the shifts appear to be linked to binary phase, this has been checked using a quantitative period-search procedure. In this procedure, three different techniques were used: the Lomb-Scargle periodogram, phase-dispersion minimization, and 2 minimization. Based primarily on comparisons with simulated data and a periodogram statistic due to Fisher, we find that we can significantly detect the orbital period in the velocity shifts. (iii) QU Car exhibits short-time-scale variations with a possible orbital trend in its uV resonance lines and/or continuum, but our data are insufficient to confirm the orbital nature of the variations. It is argued, on general grounds, that orbital-phase-linked variability of the UV resonance lines is more easily accounted for if it is due to departures from axisymmetry of the UV line emission from the accretion disc. The amplitudes of the velocity shifts suggest an inner disc location for this asymmetry in AH Her. The possibility of a secondary (uV) hotspot due to the interaction of the mass-transfer stream with the inner disc is considered. Key words: accretion, accretion discs - line: profiles - binaries: close - novae, cataclysmic variables - ultraviolet: stars.

Affiliated with

Also associated with

No associations

Rating

Time Variability in the Ultraviolet Resonance Lines of the Cataclysmic Variables Mu-Centauri Ah-Herculis and Qu-Carinae does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Time Variability in the Ultraviolet Resonance Lines of the Cataclysmic Variables Mu-Centauri Ah-Herculis and Qu-Carinae, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Time Variability in the Ultraviolet Resonance Lines of the Cataclysmic Variables Mu-Centauri Ah-Herculis and Qu-Carinae will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1237903