Astronomy and Astrophysics – Astrophysics – Galaxy Astrophysics
Scientific paper
2011-01-18
Astronomy and Astrophysics
Astrophysics
Galaxy Astrophysics
9 pages, 8 figures, accepted for publication in MNRAS
Scientific paper
The most recent observational evidence seems to indicate that giant molecular clouds are predominantly gravitationally unbound objects. In this paper we show that this is a natural consequence of a scenario in which cloud-cloud collisions and stellar feedback regulate the internal velocity dispersion of the gas, and so prevent global gravitational forces from becoming dominant. Thus, while the molecular gas is for the most part gravitationally unbound, local regions within the denser parts of the gas (within the clouds) do become bound and are able to form stars. We find that the observations, in terms of distributions of virial parameters and cloud structures, can be well modelled provided that the star formation efficiency in these bound regions is of order 5 - 10 percent. We also find that in this picture the constituent gas of individual molecular clouds changes over relatively short time scales, typically a few Myr.
Burkert Andreas
Dobbs Clare L.
Pringle James E.
No associations
LandOfFree
Why are most molecular clouds not gravitationally bound? 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 Why are most molecular clouds not gravitationally bound?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Why are most molecular clouds not gravitationally bound? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-286726