Search for EUV emission from hot subdwarfs in the ROSAT wide-field camera survey
Open Access
- 1 May 1992
- journal article
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 256 (1) , 1-7
- https://doi.org/10.1093/mnras/256.1.1
Abstract
We have searched for positional coincidences of catalogued hot subdwarfs with sources detected in the ROSAT wide-field camera (WFC) EUV survey. We find six such coincidences. Optical follow-up observations reveal four of these stars to be hot DA white dwarfs (plus one other, less certain DA), previously misclassified as subdwarfs. These five are all within the 90 per cent confidence levels of the WFC source positions, and are therefore reliable identifications with a class of sources known to be detectable EUV emitters. The remaining star is confirmed to be a hot, helium-rich subdwarf. This star lies just outside the 90 per cent confidence level of the weak WFC source position. We discuss the possibility that this could be the first detection of EUV emission from a hot subdwarf. Upper limits are derived for several well-known, brighter hot subdwarfs which were not detected in the WFC survey.Keywords
This publication has 0 references indexed in Scilit: