Astronomy and Astrophysics – Astrophysics – Galaxy Astrophysics
Scientific paper
2009-10-02
A&A vol 504, 2009, page 883
Astronomy and Astrophysics
Astrophysics
Galaxy Astrophysics
8 pages, 7 figures, accepted for publication in A&A
Scientific paper
10.1051/0004-6361/200911797
Supersonic turbulence in molecular clouds is a dominant agent that strongly affects the clouds' evolution and star formation activity. Turbulence may be initiated and maintained by a number of processes, acting at a wide range of physical scales. By examining the dynamical state of molecular clouds, it is possible to assess the primary candidates for how the turbulent energy is injected. The aim of this paper is to constrain the scales at which turbulence is driven in the molecular interstellar medium, by comparing simulated molecular spectral line observations of numerical magnetohydrodynamic (MHD) models and molecular spectral line observations of real molecular clouds. We use principal component analysis, applied to both models and observational data, to extract a quantitative measure of the driving scale of turbulence. We find that only models driven at large scales (comparable to, or exceeding, the size of the cloud) are consistent with observations. This result applies also to clouds with little or no internal star formation activity. Astrophysical processes acting on large scales, including supernova-driven turbulence, magnetorotational instability, or spiral shock forcing, are viable candidates for the generation and maintenance of molecular cloud turbulence. Small scale driving by sources internal to molecular clouds, such as outflows, can be important on small scales, but cannot replicate the observed large-scale velocity fluctuations in the molecular interstellar medium.
Brunt Chris M.
Heyer Mark H.
Mac Low Mordecai-Mar
No associations
LandOfFree
Turbulent Driving Scales in Molecular Clouds 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 Turbulent Driving Scales in Molecular Clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Turbulent Driving Scales in Molecular Clouds will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-26337