X-RAY-EMISSION FROM HERBIG AE BE STARS - A ROSAT SURVEY/

Citation
H. Zinnecker et T. Preibisch, X-RAY-EMISSION FROM HERBIG AE BE STARS - A ROSAT SURVEY/, Astronomy and astrophysics, 292(1), 1994, pp. 152-164
Citations number
71
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
00046361
Volume
292
Issue
1
Year of publication
1994
Pages
152 - 164
Database
ISI
SICI code
0004-6361(1994)292:1<152:XFHABS>2.0.ZU;2-M
Abstract
We have observed 14 Herbig Ae/Be stars in X-rays with the ROSAT PSPC ( 0.1 - 2.4 keV). In addition, we obtained data from the ROSAT archive f or 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, H R5999/6000, and Z CMa. This is surprising, since Ae/Be stars, being pr edominantly radiative, are unlikely to sustain dynamo magnetic fields and coronal heating. We have investigated possible correlations betwee n the X-ray luminosity and other stellar parameters like L(bol), spect ral type, stellar rotation and winds. We suspect that the origin of th e X-ray emission is likely to be related to the stellar wind, although other explanations (e.g. unresolved T Tauri companions) are also disc ussed. Some Ae/Be stars are known to be the exciting sources of high-v elocity jets, but none of the jets themselves were detected in X-rays. In several cases, the X-ray images revealed a small cluster of source s, presumably lower mass pre-main-sequence objects that surround the m ore massive Ae/Be stars.