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arXiv · 0902.0457

Discovery of an old photoevaporating disk in sigma Orionis

E. Rigliaco·A. Natta·S. Randich·G. Sacco
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Abstract

The photoevaporation of circumstellar disks is a powerful process in the disk dissipation at the origin of the Orion proplyds. This Letter reports the first detection of a photoevaporating disk in the final but long-lasting phase of its evolution. The disk is associated to a low-mass T Tauri member of the sigma Orionis Cluster. It is characterized by a very low (if any) accretion rate and by a tenuous (Mloss ~ 10^{-9} Msun/yr) photoevaporation wind, which is unambiguously detected in the optical spectrum of the object. The wind emits strong forbidden lines of [SII] and [NII] because the low-mass star is close to a powerful source of ionizing photons, the O9.5 star sigma Ori.

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E. Rigliaco, A. Natta, S. Randich, G. Sacco. 2009-02-03. Discovery of an old photoevaporating disk in sigma Orionis. https://doi.org/10.1051/0004-6361%2F200811535

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