Observational clues for a role of circumstellar accretion in PMS X-ray activity

Abstract

We revisit the published analyses of ROSAT X-ray observations of the star forming regions NGC 2264 and Chamaeleon I (~3 and ~5 Myr old respectively) in the light of newly published optical data. At odds with previous results on Chamaeleon I members, we find that low mass stars in both regions have near-saturated emission levels. Similarly to what previously found in the Orion Nebula Cluster, Weak Line T-Tauri Stars in NGC 2264 and in the Chamaeleon I cloud have higher X-ray activity levels respect to Classical T Tauri Stars, arguing in favor of a role of the disk and/or accretion in determining X-ray emission.

arXiv comment12 pages, 9 figures, accepted by A&A

References in corpus (4)

• Evidence for Accretion: High-Resolution X-ray Spectroscopy of the Classical T Tauri Star TW Hydrae
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