Six Myths on the Virial Theorem for Interstellar Clouds

Details Six Myths on the Virial Theorem for Interstellar Clouds Six Myths on the Virial Theorem for Interstellar Clouds

2006-06-05

arxiv.org/abs/astro-ph/0606071v2

Mon.Not.Roy.Astron.Soc.372:443,2006

Astronomy and Astrophysics

Astrophysics

Accepted by MNRAS. 9 pages, no figures

Scientific paper

10.1111/j.1365-2966.2006.10880.x

It has been paid little or no attention to the implications that turbulent fragmentation has on the validity of at least six common assumptions on the Virial Theorem (VT), which are: (i) the only role of turbulent motions within a cloud is to provide support against collapse, (ii) the surface terms are negligible compared to the volumetric ones, (iii) the gravitational term is a binding source for the clouds, (iv) the sign of the second-time derivative of the moment of inertia determines whether the cloud is contracting or expanding, (v) interstellar clouds are in Virial Equilibrium (VE), and (vi) Larson's (1981) relations are the observational proof that clouds are in VE. Interstellar clouds cannot fulfill these assumptions, however, because turbulent fragmentation will induce flux of mass, moment and energy between the clouds and their environment, and will favor local collapse while may disrupt the clouds within a dynamical timescale. It is argued that, although the observational and numerical evidence suggests that interstellar clouds are not in VE, the so-called ``Virial Mass'' estimations, which actually should be called ``energy-equipartition mass'' estimations, are good order-of magnitude estimations of the actual mass of the clouds just because observational surveys will tend to detect interstellar clouds appearing to be close to energy equipartition. However, since clouds are actually out of VE, as suggested by asymmetrical line profiles, they should be transient entities. These results are compatible with observationally-based estimations for rapid star formation. , and call into question the models for the star formation efficiency based on clouds being in VE.

Affiliated with

Also associated with

No associations

Rating

Six Myths on the Virial Theorem for Interstellar 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 Six Myths on the Virial Theorem for Interstellar Clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Six Myths on the Virial Theorem for Interstellar Clouds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-541624