Phase-resolved spectroscopy of the helium dwarf nova 'SN 2003aw' in quiescence |
| |
| Authors: | G H A Roelofs P J Groot T R Marsh D Steeghs G Nelemans |
| |
| Institution: | Department of Astrophysics, Radboud University, PO Box 9010, 6500 GL Nijmegen, the Netherlands;Department of Physics, University of Warwick, Coventry CV4 7AL;Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02318, USA |
| |
| Abstract: | High time resolution spectroscopic observations of the ultracompact helium dwarf nova 'SN 2003aw' in its quiescent state at V ～ 20.5 reveal its orbital period at 2027.8 ± 0.5 s or 33.80 min. Together with the photometric 'superhump' period of 2041.5 ± 0.5 s , this implies a mass ratio q ≈ 0.036 . We compare both the average and time-resolved spectra of 'SN 2003aw' and Sloan Digital Sky Survey (SDSS) J124058.03?015919.2. Both show a DB white dwarf spectrum plus an optically thin, helium-dominated accretion disc. 'SN 2003aw' distinguishes itself from the SDSS source by its strong calcium H & K emission lines, suggesting higher abundances of heavy metals than the SDSS source. The silicon and iron emission lines observed in the SDSS source are about twice as strong in 'SN 2003aw'. The peculiar 'double bright spot' accretion disc feature seen in the SDSS source is also present in time-resolved spectra of 'SN 2003aw', albeit much weaker. |
| |
| Keywords: | accretion accretion discs binaries: close stars: individual: SN 2003aw stars: individual: SDSS J124058 03?015919 2 novae cataclysmic variables |
|
|
