X-ray emission from Lindroos binary systems
Abstract
We present a study of the X-ray emission from binary systems extracted from the Lindroos catalogue (Lindroos 1986) based on the ROSAT All-Sky survey as well as ROSAT PSPC and HRI pointings. The studied sample consists of visual binary systems comprised of early-type primaries and late-type secondaries. The ages of the systems were determined by Lindroos (1985) from uvbybeta photometry of the primaries. These ages range between 33 and 135 Myr, so if the late-type secondaries are physically bound to the early-type primaries, they could be Post-T Tauri stars (PTTS). We have found strong X-ray emission from several secondaries. This fact together with their optical and IR data, make them bona fide PTTS candidates. We have also detected X-ray emission from several early-type primaries and, in particular, from most of the late-B type stars. Because their HRI hardness ratios are similar to those from resolved late-type stars, the presence of an unresolved late-type companion seems to be the cause of this emission.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 2000
- DOI:
- 10.48550/arXiv.astro-ph/0005348
- arXiv:
- arXiv:astro-ph/0005348
- Bibcode:
- 2000A&A...359..227H
- Keywords:
-
- STARS: BINARIES: VISUAL;
- STARS: EARLY-TYPE;
- STARS: PRE-MAIN SEQUENCE;
- STARS: INDIVIDUAL: HR 4796;
- X-RAYS: STARS;
- Astrophysics
- E-Print:
- 17 pages, 6 figures, accepted by A&