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N. Craig, D. Christian, J. Dupuis, and B. Roberts
Center for EUV Astrophysics, 2150 Kittredge Street, University
of California, Berkeley, CA 94720
We present optical identifications of 30 previously unidentified extreme ultraviolet (EUV) and soft x-ray sources coinciding with the position of faint sources detected during the all-sky surveys of the Extreme Ultraviolet Explorer (EUVE) in the 58-174 A (0.071-0.214 keV) band and of the ROSAT Position Sensitive Proportional Counter (PSPC) in the 5-120 A (0.1-2.4 keV x-ray) band. We present low-resolution spectra of the possible optical counterparts of the x-ray and EUVE sources obtained with the 1.5 m telescope at CTIO in 1995 May and December and 1996 February. The optical counterparts for 23 sources are identified as late-type (dKe and dMe) stars, and 4 are identified as new DA white dwarfs. All spectra of sources identified as late-type stars show the Balmer series and Ca H and K lines in emission, indicating the signature of chromospheric activity. For the white dwarfs, the joint detection by the ROSAT PSPC and the EUVE Lexan band indicates that they have a low-abundance of metals and that their EUV emission is mostly attenuated by the local interstellar medium (ISM).
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