Thermal evolution of a gas with the primordial chemical composition, contracting under the influence of gravitation

Journal Article · Sat Nov 01 04:00:00 EST 1980 · Sov. Astron. (Engl. Transl.); (United States)

OSTI ID:6420059

Shchekinov, Y A; Edel'man, M A

The thermal evolution is calculated for a spherical gas cloud with the primordial chemical composition, contracting in the free-fall mode. The initial densities are varied in the range of 0.1--10 cm/sup -3/ and initial temperatures in the range of (3--10) x 10/sup 3/ /sup 0/K. The conditions required for the formation of H2 molecules in the amounts required for cooling of the protogalactic gas to low temperatures Troughly-equal10/sup 2/ /sup 0/K and for successful star formation are investigated. The influence of the radiation produced by protoclusters of galaxies on the amount of molecular hydrogen in the protogalactic material is examined. The destruction of H2 molecules by this radiation is so efficient that when z> or approx. =2 the molecular hydrogen is able to cool the gas only when n/sub 0/ = 10 cm/sup -3/, whereas most of the material in a protocluster has a lower density. When n/sub 0/<10 cm/sup -3/ and z> or approx. =2 the gas contracts isothermally with Troughly-equal8000 /sup 0/K and star formation in it is hindered. The content of heavy elements required to cool the gas of the protogalaxy to T< or approx. =10/sup 2/ /sup 0/K is estimated.

• Research Organization: Rostov State University
• OSTI ID: 6420059
• Journal Information: Sov. Astron. (Engl. Transl.); (United States), Journal Name: Sov. Astron. (Engl. Transl.); (United States) Vol. 24:6; ISSN SAAJA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics &amp; Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHEMICAL COMPOSITION
CHEMISTRY
COSMOCHEMISTRY
GALACTIC EVOLUTION
GRAVITATIONAL FIELDS
THERMODYNAMICS