AAS Meeting #193 - Austin, Texas, January 1999
Session 103. EUVE Observations and Modeling of X-Ray Sources
Display, Saturday, January 9, 1999, 9:20am-4:00pm, Exhibit Hall 1

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[103.03] Selected EUVE Timing Results on AM Herculis Binaries

D. J. Christian (CSC/STScI), S. Vennes (SSL/UCB \& ATC, ANU, Canberra, AU)

We present Extreme Ultraviolet Explorer (EUVE) timing results for AM Her, VV Pup, and EUVE J2115-586. We obtained an EUVE target of opportunity observation of AM Her in a high accretion state between 04 August 09:42 -05 August 12:28 1998 UT. The Deep Survey (DS) Lexan filter (~100 Å) count rate was 2.57±0.05 cts/sec. This observation was made simultaneously with Rossi-XTE with the goal of testing correlations in the EUV and X-ray bands. We will present EUVE and RXTE PCA phased light curves and timing studies. We have searched archival EUVE data of VV Pup (February 1993) for the 1-3 sec optical quasi-periodic oscillations (QPO). We found no significant features in the 0.3-1.0 Hz range for the total light curve and light curves separated as a function of orbital phase. We also searched archival EUVE data of AM Her (September 1993 and March 1995) for the ~6 minute QPO reported by Stella et al. 1986 using Einstein observations. All features found in the ~6 minute range are higher harmonics of the beating between the AM Her and EUVE orbital periods. We also present our October 1997 EUVE observation of asynchronous polar EUVE J2115-586. The source was in a low state with a DS Lexan count rate of 7±3 cts/ksec. The EUVE light curve favors a period of 110.4 minutes, similar to the one derived from optical observations by Vennes et al. 1997, but further observations are needed. This research is supported by NASA Grant NAG5-7013.


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