Radiation-hydrodynamical simulations of massive star formation using Monte Carlo radiative transfer II. The formation of a 25 solar-mass star
Monthly Notices of the Royal Astronomical Society
Oxford University Press (OUP)
© 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
We present a numerical simulation of the formation of a massive star using Monte- Carlo-based radiation hydrodynamics (RHD). The star forms via stochastic disc ac- cretion and produces fast, radiation-driven bipolar cavities. We nd that the evolution of the infall rate (considered to be the mass ux across a 1500 au spherical boundary), and the accretion rate onto the protostar, are broadly consistent with observational constraints. After 35 kyr the star has a mass of 25M and is surrounded by a disc of mass 7 M and 1500 au radius, and we nd that the velocity eld of the disc is close to Keplerian. Once again these results are consistent with those from recent high-resolution studies of discs around forming massive stars. Synthetic imaging of the RHD model shows good agreement with observations in the near- and far-IR, but may be in con ict with observations that suggests that MYSOs are typically circularly symmetric on the sky at 24.5 m. Molecular line simulations of a CH3CN transition compare well with observations in terms of surface brightness and line width, and indicate that it should be possible to reliably extract the protostellar mass from such observations.
The calculations for this paper were performed on the University of Exeter Supercomputer, a DiRAC Facility jointly funded by STFC, the Large Facilities Capital fund of BIS, and the University of Exeter, and on the Complexity DiRAC Facility jointly funded by STFC and the Large Facilities Capital Fund of BIS. TJH and TAD acknowledge funding from Exeter's STFC Consolidated Grant (ST/M00127X/1). We thank Takashi Hosokawa for kindly providing us with the protostellar evolutionary model. We are grateful to Maite Beltran for providing the data for Figure 4, and we thank Dave Acreman, John Ilee and Tom Haworth for useful discussions. We thank the anonymous referee for a helpful report.
This is the author accepted manuscript. The final version is available from OUP via the DOI in this record.
Published online 16 June 2017