Simulations of protostellar collapse using multigroup radiation hydrodynamics: II. The second collapse

• Published in: Astronomy and astrophysics (Berlin) 2013-09, Vol.557, p.np-np
• Main Authors: Vaytet, Neil, Chabrier, Gilles, Audit, Edouard, Commercon, Benoit, Masson, Jacques, Ferguson, Jason, Delahaye, Franck
• Format: Article
• Language: English
• Subjects: Collapse; Fluid dynamics; Fluid flow; Formations; Hydrodynamics; Radiative transfer; Simulation
• ISSN: 0004-6361; 1432-0746
• DOI: 10.1051/0004-6361/201321423

Star formation begins with the gravitational collapse of a dense core inside a molecular cloud. As the collapse progresses, the centre of the core begins to heat up as it becomes optically thick. Simulated collapsing cores without radiative transfer rapidly become thermally supported before reaching high enough temperatures and densities, preventing the formation of stars. Many simulations of protostellar collapse make use of a grey treatment of radiative transfer coupled to the hydrodynamics. In this paper, we follow up on a previous paper on the collapse and formation of Larson's first core using multigroup radiation hydrodynamics (Paper I) by extending the calculations to the second phase of the collapse and the formation of Larson's second core. Our simulations support the idea of a standard initial second core size of ~3 10[sup -3] AU and mass ~1.4 10[sup -3] M. A simple estimate of the characteristic timescale of the second core suggests that the effects of using multigroup radiative transfer may be more important in the long-term evolution of the protostar.