2004/03/30 by Christopher W. Mauche · 26 citations
Physics and Astronomy · #Accretion (finance) #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Black-body radiation #Ionization #Luminosity #Opacity #Spectral line #Stars #White dwarf #astro-ph
paper · pdf · doi:10.1086/421438
published in The Astrophysical Journal 610(1), 422-426 (IOP Publishing) · 5 pages including 3 encapsulated postscript figures; LaTeX format, uses aastex.cls and emulateapj5; accepted on 2004 March 30 for publication in The Astrophysical Journal
arxiv created 2004/03/30 · openalex publication_date 2004/07/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We have fitted the Chandra Low Energy Transmission Grating (LETG) spectrum of SS Cygni in outburst with a single-temperature blackbody suffering the photoelectric opacity of a neutral column density and the scattering opacity of an outflowing wind. We find that this simple model is capable of reproducing the essential features of the observed spectrum with the blackbody temperature T bl ≈ 250 ± 50 kK, hydrogen column density N H ≈ 5.0 × 10 19 cm -2 , fractional emitting area f ≈ 5.6 × 10 -3 , boundary layer luminosity L bl ≈ 5 × 10 33 ergs s -1 , wind velocity v ≈ 2500 km s -1 , wind mass-loss rate w ≈ 1.1 × 10 16 g s -1 , and arbitrary values of the wind ionization fractions of 20 ions of O, Ne, Mg, Si, S, and Fe. Given that in outburst the accretion disk luminosity L disk ≈ 1 × 10 35 ergs s -1 , L bl / L disk ≈ 0.05 , which can be explained if the white dwarf (or an equatorial belt thereon) is rotating with an angular velocity Ω wd ≈ 0.7 Hz, hence V rot sin i ~ 2300 km s -1 .