Collisional growth of giant molecular clouds

Journal Article · Sun Apr 15 04:00:00 EST 1979 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/156991· OSTI ID:5990241

Scoville, N Z; Hersh, K

The observation that giant molecular clouds in the inner galactic plane populate both arm and interarm regions has recently been interpreted as evidence of a very long lifetime (>10/sup 8/ years) for these clouds. An implication of this longevity is that the great masses of the clouds in the molecular ring at omega-tilde=4--8 kpc may be accumulated through cloud-cloud collisional accretion. Starting from an initial distribution of small clouds, the individual cloud masses will grow to the observed 10/sup 5/--10/sup 6/ M/sub sun/ within 10/sup 9/ years, assuming the total mass of H/sub 2/ remains constant. Continued growth will be halted at a few times 10/sup 5/ M/sub sun/, where the collisional accretion rate is balanced by the removal of H/sub 2/ into stars at a galactic rate of 2 M/sub sun/ Year/sup -1/ combined with ionization by H II regions.

• Research Organization: Department of Physics and Astronomy, University of Massachusetts, Amherst
• OSTI ID: 5990241
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 229:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COLLISIONS
COSMIC GASES
COSMIC RADIO SOURCES
CRYOGENIC FLUIDS
ELEMENTS
ERUPTIVE VARIABLE STARS
FLUIDS
GALAXIES
GASES
H2 REGIONS
HYDROGEN
INTERSTELLAR SPACE
IONIZATION
MILKY WAY
MOLECULES
NEBULAE
NONMETALS
SPACE
STAR ACCRETION
STAR EVOLUTION
STARS
SUPERNOVAE
VARIABLE STARS