The Mdot - M* relation of pre-main sequence stars: a consequence of X-ray driven disc evolution
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.
Keywords
Cite
@article{arxiv.1312.3154,
title = {The Mdot - M* relation of pre-main sequence stars: a consequence of X-ray driven disc evolution},
author = {B. Ercolano and D. Mayr and J. E. Owen and G. Rosotti and C. F. Manara},
journal= {arXiv preprint arXiv:1312.3154},
year = {2014}
}
Comments
9 pages, 6 Figures, 2 Tables, accepted by MNRAS