The Mdot - M* relation of pre-main sequence stars: a consequence of X-ray driven disc evolution
Autor: | Ercolano, B., Mayr, D., Owen, J. E., Rosotti, G., Manara, C. F. |
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Rok vydání: | 2013 |
Předmět: | |
Druh dokumentu: | Working Paper |
DOI: | 10.1093/mnras/stt2405 |
Popis: | 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. Comment: 9 pages, 6 Figures, 2 Tables, accepted by MNRAS |
Databáze: | arXiv |
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