Astronomy and Astrophysics – Astrophysics
Scientific paper
Jun 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994pasj...46l..93k&link_type=abstract
PASJ: Publications of the Astronomical Society of Japan, vol. 46, no. 3, p. L93-L96
Astronomy and Astrophysics
Astrophysics
28
Stellar Luminosity, Wolf-Rayet Stars, X Ray Spectra, Abundance, Charge Coupled Devices, Stellar Spectra, X Ray Absorption
Scientific paper
Advanced Satellite for Cosmology and Astrophysics (ASCA) observed the Wolf-Rayet binary HD 193793 (WC 7 + O4-5) in 1993 June, only 3 months after periastron passage when the WC star was nearly in front of the O star. The X-ray spectra are heavily absorbed below approximately equals 2 keV by the Wolf-Rayet wind and show a prominent emission line from He-like iron at 6.7 keV. A variable abundance Raymond-Smith model gives a temperature of kT approximately equals 3 keV (35 million K) and an equivalent hydrogen column density NH approximately equals 3 x 1022 cm-2. This column density is a factor of approximately equals 10 larger than the interstellar value, confirming that the absorption is primarily circumstellar. We derive an upper limit on the carbon abundance in the WC 7 wind of approximately equals 30 solar, and find evidence for a strong overabundance of neon as predicted by evolutionary models. The X-ray luminosity and derived column density agree well with that expected from a colliding wind shock, although comparison with a 1987 Ginga observation fails to reveal the expected change in hard flux (2-6 keV) with binary separation.
Koyama Katsuji
Maeda Yoshitomo
Nagase Fumiaki
Skinner Stephen
Tsuru Takeshi
No associations
LandOfFree
ASCA observations of the Wolf-Rayet binary HD 193793 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 ASCA observations of the Wolf-Rayet binary HD 193793, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and ASCA observations of the Wolf-Rayet binary HD 193793 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1507146