Multi--Pressure Polytropes as Models for the Structure and Stability of Molecular Clouds. I. Theory

Autor:	Christopher F. McKee, John H. Holliman
Jazyk:	angličtina
Rok vydání:	1999
Předmět:	Physics Isentropic process Molecular cloud Astronomy and Astrophysics Polytropic process Astrophysics Mechanics Superposition principle Space and Planetary Science Wave pressure Thermal Magnetic pressure Total pressure
Popis:	Molecular clouds are supported by thermal pressure, magnetic pressure, and turbulent pressure. Each of these can be modeled with a polytropic equation of state, so that overall the total pressure is the sum of the individual components. We model the turbulent pressure as being due to a superposition of Alfven waves. The theory of polytropes is generalized to allow for the flow of entropy in response to a perturbation, as expected for the entropy associated with wave pressure. The equation of state of molecular clouds is "soft", so that the properties of the clouds are generally governed by the conditions at the surface. In general, the polytropes are not isentropic, and this permits large density and pressure drops to occur between the center and the edge of the polytropes, as is observed. Comment: Submitted to ApJ with 10 figures
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::96bbce2919c5597b97c15e5ca582df73 http://arxiv.org/abs/astro-ph/9903213 Zobrazit plný text záznamu