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arXiv · 1312.3154

The Mdot - M* relation of pre-main sequence stars: a consequence of X-ray driven disc evolution

B. Ercolano·D. Mayr·J. E. Owen·G. Rosotti·C. F. Manara
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Abstract

We analyse current measurements of accretion rates onto pre-main sequence stars as a function of stellar mass, and conclude that the steep dependance of accretion rates on stellar mass is real and not driven by selection/detection threshold, as has been previously feared. These conclusions are reached by means of statistical tests including a survival analysis which can account for upper limits. The power-law slope of the Mdot-M* relation is found to be in the range of 1.6-1.9 for young stars with masses lower than 1 Msun. The measured slopes and distributions can be easily reproduced by means of a simple disc model which includes viscous accretion and X-ray photoevaporation. We conclude that the Mdot-M* relation in pre-main sequence stars bears the signature of disc dispersal by X-ray photoevaporation, suggesting that the relation is a straight- forward consequence of disc physics rather than an imprint of initial conditions.

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B. Ercolano, D. Mayr, J. E. Owen, G. Rosotti, C. F. Manara. 2013-12-11. The Mdot - M* relation of pre-main sequence stars: a consequence of X-ray driven disc evolution. https://doi.org/10.1093/mnras%2Fstt2405

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