Astronomy and Astrophysics – Astrophysics
Scientific paper
Oct 1985
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1985apj...297...61b&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 297, Oct. 1, 1985, p. 61-75.
Astronomy and Astrophysics
Astrophysics
51
Dynamic Stability, Galactic Evolution, Galactic Structure, Gravitational Constant, Interstellar Space, Spiral Galaxies, Astronomical Models, Gravitational Collapse
Scientific paper
The dynamics of self-gravitating gaseous density perturbations in the tightly wound spiral-arm model of the forcing potential (Brown 1969) is investigated. The cloud ensemble of the cold phase of the interstellar medium is regarded as a collisional gas whose 'molecules' are the clouds themselves, and the dynamical evolution of density perturbations is calculated assuming this gas obeys a polytropic pressure-density law. It is suggested that the formation of extreme Population I objects found predominantly along the arms of Sb/Sc systems is regulated by an overall energy balance in the cloud fluid. A single parameter is found which appears to characterize the flow's gravitational response to perturbations; this spiral parameter, Q-sub-sp, differs from the Toomre Q parameter by a factor of the square root of the density enhancement at the shock. It is necessary but not sufficient that Q-sub-sp be less than unity for significant growth to occur.
Balbus Steven A.
Cowie Lennox L.
No associations
LandOfFree
On the gravitational stability of the interstellar medium in spiral arms does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with On the gravitational stability of the interstellar medium in spiral arms, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the gravitational stability of the interstellar medium in spiral arms will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1545552