ORFEUS and EUVE observations of AM herculis

Conference · Thu Apr 06 04:00:00 EDT 1995

OSTI ID:79750

Mauche, C W ^[1]; Paerels, F B.S. ^[2]; Raymond, J C ^[3]

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1. Lawrence Livermore National Lab., CA (United States)
2. Univ. of California, Berkeley, CA (United States). Dept. of Physics
3. Center for Astrophysics, Cambridge, MA (United States)

Far-UV spectra of AM Her in a high optical state were obtained in 1993 September with the University of California, Berkeley (UCB) spectrometer aboard the ORFEUS telescope. The UCB spectrometer has a spectral resolution {lambda}/{Delta}{lambda} 3000 and covers the 390-1170 {Angstrom} bandpass, but interstellar absorption leaves no detectable -flux below the Lyman limit. Spectra of AM Her were acquired during the intervals 04:19:40-04:36:26 UT on September 16 and 08:34:03-09:09:06 UT on September 17 of 1993. The corresponding magnetic phases are 0.75-0.84 and 0.88-1.07 according to the linear polarization ephemeris of S. Tapia. The main spectral features are the 0 VI doublet, C III {lambda}977, and He II {lambda}1085 (Balmer {gamma}). The bright C III {lambda}1176 multiplet, which is detected by IUE, is at the very end of the spectrum. At the full spectral resolution of the instrument, the 0 VI doublet shows broad and narrow components similar to that of the optical emission lines. The intensity ratio of the narrow component of the 0 VI doublet is {approximately} 1.3:1, much closer to the optically thick limit of 1:1 than the optically thin ratio of 2:1.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 79750
• Report Number(s): UCRL-JC--120557; CONF-950189--1; ON: DE95012456
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ASTRONOMY
ASTROPHYSICS
BINARY STARS
EXTREME ULTRAVIOLET SPECTRA
FAR ULTRAVIOLET RADIATION
TELESCOPES