ROSAT observations of stellar clusters.
Abstract
Stellar clusters provide excellent laboratories for stellar astronomers since they consist of coeval populations of stars of varied mass but fixed distance, chemical composition and age. ROSAT PSPC observations of about a dozen stellar clusters, ranging in age from ≡20 to ≡600 Myr, have provided an enormous amount of data with which questions left unanswered by Einstein observations can be addressed. It now seems clear that X-ray luminosity distribution functions are dependent on both age and mass. This is attributed to mass-dependent spindown timescales which give rise to age-dependent distributions of rotational velocities. The relation between coronal activity and stellar rotation is more explicitly demonstrated by plotting Lx/Lbol as functions of mass and v sin i; these plots show saturation for rapidly-rotating late-type stars.
- Publication:
-
Roentgenstrahlung from the Universe
- Pub Date:
- February 1996
- Bibcode:
- 1996rftu.proc....1C
- Keywords:
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- Star Clusters: X Rays;
- Star Clusters: Stellar Activity;
- Star Clusters: Stellar Rotation