The Thermal Structure of a Protostellar Envelope

Author(s)
Yaroslav Pavlyuchenkov, Andrey Zhilkin, Eduard Vorobiev, A. M. Fateeva
Abstract

A numerical hydrodynamical model for the evolution of spherically symmetric collapsing clouds, designed for the calculation of the thermal structure of these objects in both the prestellar and protostellar stages of their evolution, is presented. Distinctive features of the model include the possibility of independently describing the temperatures of the gas and dust, which is extremely important when calculating the thermal structure of prestellar and protostellar clouds, and the account of the radiation flux from the central protostar. This model is used to compare the theoretical density and temperature distributions with observations for nearby sites of star formation obtained with the Herschel Space Observatory. Application of the diffusion approximation with a flux limiter describes well the radial density and temperature distributions in protostellar clouds. However, significant differences between the model and observational density profiles were found for prestellar stages, suggesting the presence of appreciable deviations from equilibrium in the prestellar clouds. An approximate method for calculating the thermal structure of a cloud based on the adaptive τ-approximation is presented. Application of the τ-approximation yields good agreement with the diffusion approximation for the prestellar phase, but produces appreciable discrepancies for the protostellar phase, when the thermal structure of the accreting envelope is determined by the radiation of the protostar.

Organisation(s)
Department of Astrophysics
External organisation(s)
Russian Academy of Sciences, Chelyabinsk State University, Southern Federal University
Journal
Astronomy Reports
Volume
59
Pages
133-144
No. of pages
12
ISSN
1063-7729
DOI
https://doi.org/10.1134/S1063772915020067
Publication date
02-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/ef230b80-5dde-4a50-b84c-0db9c8a4cafc