Recent Science Highlights

8 April 1995

• Using data from the public archive of the EUVE all-sky survey, Dr. Antonella Fruscione has systematically searched for short wavelength (58-174 Å) EUV emission around approximately 2500 distinct positions in the sky corresponding to known X-ray emitting extragalactic sources. She finds that twenty X-ray galaxies are EUV bright and were detected with significance above 4 sigma during the EUVE survey: eight (six Seyfert galaxies and two BL Lacertae objects) are reported for the first time as sources of EUV emission. Sixty-eight additional galaxies are detected with a lower significance (sigma between 3 and 4), but the list is affected by a high percentage of spurious sources. The paper has been recently submitted to the Astrophysical Journal.
• Dr. Jurgen Schmitt, Dr. Jeremy Drake, and Dr. Robert Stern have summarized their finding about resonant scattering in a paper recently submitted to ApJ Letters entitled "EUV Line Emission From Cool Stars: Resonantly Scattered or Not - That is the Question!". The authors argue, based upon statistical analysis of fluctuations in the EUVE spectrum of Procyon and ROSAT X-ray data, that resonance scattering (as proposed by Dr. Schrijver and collaborators in a paper published in Astromony and Astrophysics) appears not to be relevant for the interpretation of the EUV and X-ray spectra of cool inactive stars. Instead, a number of as yet unidentified spectral lines not included in current plasma codes produces a false "continuum" in excess of that predicted.