New cataclysmic variables from the ROSAT All-Sky Survey.
Abstract
We report the discovery of 7 new cataclysmic variables in the low galactic latitude (|b|<=20deg) part of the ROSAT all sky survey. All but one of these new sources have been optically identified. These interacting binaries were either found in subsets of sources chosen for their particular X-ray/optical properties or in specific areas selected for statistical studies. The present sample is therefore not representative of the overall content of the survey. One, or probably two, of these new cataclysmic variables are intermediate polars. RXJ0028.8+5917 (P_s_=312.8s) which exhibits the usual hard X-ray spectrum typical of this class has an orbital period of 4-5 hours and is probably identical to 1H0025+588/4U0027+59. The other pulsating source, RXJ1914.4+2456 (P_s_=567.7s) awaits optical identification in order to confirm its cataclysmic variable nature. RXJ1914.4+2456 has an X-ray energy distribution dominated by a super-soft component which may be fitted with a 43eV black body. RXJ1914.4+2456 thus probably belongs to the new class of soft intermediate polars discovered by ROSAT. Our deep optical search failed to reveal a counterpart brighter than V=~19.7. This upper limit is consistent with the source being a cataclysmic variable if the large amount of absorption detected at X-ray energies is mainly of interstellar origin. Three other sources, RXJ0502.8+1624, RXJ1141.3-6410 and RXJ2123.7+4217 exhibit X-ray and optical properties suggesting magnetic systems.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 1996
- Bibcode:
- 1996A&A...307..459M
- Keywords:
-
- STARS: CATACLYSMIC VARIABLES;
- X-RAY: STARS