X-ray emission from Herbig Ae/Be stars: a ROSAT survey.
Abstract
We have observed 14 Herbig Ae/Be stars in X-rays with the ROSAT PSPC (0.1-2.4keV). In addition, we obtained data from the ROSAT archive for 7 Herbig Ae/Be stars. As a result, 11 of the 21 Herbig Ae/Be stars studied here have been detected as X-ray sources, among them AB Aur, HR 5999/6000, and Z CMa. This is surprising, since Ae/Be stars, being predominantly radiative, are unlikely to sustain dynamo magnetic fields and coronal heating. We have investigated possible correlations between the X-ray luminosity and other stellar parameters like L_bol_, spectral type, stellar rotation and winds. We suspect that the origin of the X-ray emission is likely to be related to the stellar wind, although other explanations (e.g. unresolved T Tauri companions) are also discussed. Some Ae/Be stars are known to be the exciting sources of high-velocity jets, but none of the jets themselves were detected in X-rays. In several cases, the X-ray images revealed a small cluster of sources, presumably lower mass pre-main-sequence objects that surround the more massive Ae/Be stars.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- December 1994
- Bibcode:
- 1994A&A...292..152Z
- Keywords:
-
- A Stars;
- B Stars;
- Emission Spectra;
- Pre-Main Sequence Stars;
- X Ray Astronomy;
- X Ray Stars;
- X Rays;
- Correlation;
- Rosat Mission;
- Satellite Imagery;
- Spaceborne Astronomy;
- Stellar Coronas;
- Stellar Luminosity;
- Stellar Rotation;
- Stellar Winds;
- X Ray Spectra;
- Astronomy;
- X-RAYS: STARS;
- STARS: EMISSION-LINE;
- STARS: STELLAR CORONAE;
- STARS: PRE-MAIN-SEQUENCE