2002/02/18 by H. Bearda, Henk Bearda, Wouter Hartmann +12
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Bolometer #Energy spectrum #Galaxy #Ionization #Luminosity #Nuclear physics #Optics #Physics #Plasma #Spectrometer #Spectrum (functional analysis) #Stellar, planetary, and galactic studies #Telescope #astro-ph
paper · pdf · doi:10.1051/0004-6361:20020104
accepted for publication in Astronomy and Astrophysics, 6 pages, 2 figures
arxiv created 2002/02/18 · openalex publication_date 2002/04/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present the X-ray spectrum of / , obtained with the Medium Energy Grating spectrometer of the Chandra X-ray Telescope. The simplest models used by earlier authors, stellar atmospheres in combination with a thermal plasma in collisional ionization equilibrium, cannot explain the spectrum. Neither does a photo-ionized plasma. We identify P Cygni profiles of Fe XVII and O VIII, from which we conclude that these lines arise in a wind. We conclude that major uncertainty exists about the bolometric luminosity of , and perhaps of supersoft sources in general, so that the theoretical prediction that this luminosity derives from steady nuclear burning cannot be verified.