A Radio Survey of Older T Tauri Stars in the η Chamaeleontis Cluster

Publications of the Astronomical Society of Australia

Eric E. Mamajek¹ 

[1] Warrick A. Lawson

关键词: open clusters and associations: η Chamaeleontis;    stars: pre-main-sequence;    radio continuum: stars;   

DOI  :  10.1071/AS99257

学科分类：天文学(综合)

来源: CSIRO

【 摘 要 】

A radio continuum survey of X-ray-identified weak-lined T Tauri stars (WTTs) in the newly-discovered η Chamaeleontis cluster has been completed using the Australia Telescope Compact Array (ATCA). The 10 known WTTs in the cluster form a unique sample of codistant late-type pre-main-sequence stars with ages of ~8 Myr and masses ranging from 0·1–1·0 M⊙. Our survey detected none of the 10 X-ray-emitting WTTs with 3σ sensitivity limits at 4·8 and 8·6 GHz (6·2 and 3·5 cm) of typically 0·4 mJy, corresponding to a radio luminosity of 4·5 ×1015 erg Hz−1 s−1. Rotation periods for these stars indicate that they are not, as a group, fast-rotating stars. The non-detection in the radio bands supports the findings of other radio surveys of inhomogeneous samples of young stars, where radio emission is fairly common (10–30%) among very young T Tauri stars across all late spectral types, but confined to rapidly-rotating F-G-K stars amongst older zero-age main sequence stars. Rotation, more than youth, appears to be the key to radio emission in young stars.

【 授权许可】

Unknown