Episodic disk accretion in the halo of the 'old' Pre-Main Sequence cluster Eta Chamaeleontis - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate




Episodic disk accretion in the halo of the 'old' Pre-Main Sequence cluster Eta Chamaeleontis - Astrophysics > Solar and Stellar Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We present multi-epoch medium-resolution observations of two M4.5 candidatemembers in the halo of the ~8 Myr Eta Chamaeleontis open cluster. Over sixmonths of observations both stars exhibited variations in their H-alpha lineprofiles on timescales of days to months, with at least one episode ofsubstantial activity attributable to accretion from a circumstellar disk. Wederive an accretion rate ~10^-8.7 Msun-yr for this event, with a rate of~10^-10.6 Msun-yr in quiescence. Episodic accretion like that observed heremeans existing surveys of accreting Weak-lined T-Tauri Stars in young clustersare likely incomplete and that gas dissipation timescales calculated from thefraction of accreting objects are underestimates.



Author: Simon J. Murphy, Warrick A. Lawson, Michael S. Bessell, Daniel D. R. Bayliss

Source: https://arxiv.org/







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