Conditions for the formation of massive stars through nonspherical accretion

Journal Article · Sun Oct 01 04:00:00 EDT 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/167919· OSTI ID:5019535

Nakano, Takenori ^[1]

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1. Kyoto Univ. (Japan)

Formation of massive stars through spherical accretion has been predicted to occur only in clouds which are nearly dust-free and can provide an extremely high accretion rate. It is shown that such severe restrictions are effectively removed with nonspherical accretion. By the effects of magnetic fields, rotation, and so on, the contracting envelope usually becomes rather flat. With such a configuration the thermal radiation converted from the stellar radiation by dust near its sublimation zone easily escapes from the envelope and then hardly affects the motion of dust and gas. Consequently, the gas falls nearly freely to the sublimation zone. The steady inflow occurs only when the dynamical pressure of this motion is greater than the stellar radiation pressure at this zone. With the present model the accretion onto a stellar core of 100 solar mass occurs when the accretion rate is greater than 0.0001 solar mass/yr, 50 times smaller than the rate with spherical accretion. No special restrictions on grain abundances are required, in contrast to spherical accretion. The causes for the rarity of massive stars are discussed. 59 refs.

• OSTI ID: 5019535
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 345; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC DUST
COSMIC GASES
DUSTS
ELECTROMAGNETIC RADIATION
FLUIDS
GALAXIES
GASES
INTERSTELLAR SPACE
MAGELLANIC CLOUDS
MAGNETIC FIELDS
MAIN SEQUENCE STARS
MASS
MATHEMATICAL MODELS
MILKY WAY
RADIATION PRESSURE
RADIATIONS
SPACE
STAR ACCRETION
STAR EVOLUTION
STAR MODELS
STARS
STELLAR RADIATION
THERMAL RADIATION