Gravitational Collapse and Filament Formation: Comparison with the Pipe Nebula

Details Gravitational Collapse and Filament Formation: Comparison with the Pipe Nebula Gravitational Collapse and Filament Formation: Comparison with the Pipe Nebula

2009-09-10

arxiv.org/abs/0909.2018v1

Astronomy and Astrophysics

Astrophysics

Galaxy Astrophysics

10 pages, 4 figures, accepted by ApJ

Scientific paper

Recent models of molecular cloud formation and evolution suggest that such clouds are dynamic and generally exhibit gravitational collapse. We present a simple analytic model of global collapse onto a filament and compare this with our numerical simulations of the flow-driven formation of an isolated molecular cloud to illustrate the supersonic motions and infall ram pressures expected in models of gravity-driven cloud evolution. We apply our results to observations of the Pipe Nebula, an especially suitable object for our purposes as its low star formation activity implies insignifcant perturbations from stellar feedback. We show that our collapsing cloud model can explain the magnitude of the velocity dispersions seen in the $^{13}$CO filamentary structure by Onishi et al. and the ram pressures required by Lada et al. to confine the lower-mass cores in the Pipe nebula. We further conjecture that higher-resolution simulations will show small velocity dispersions in the densest core gas, as observed, but which are infall motions and not supporting turbulence. Our results point out the inevitability of ram pressures as boundary conditions for molecular cloud filaments, and the possibility that especially lower-mass cores still can be accreting mass at significant rates, as suggested by observations.

Affiliated with

Also associated with

No associations

Rating

Gravitational Collapse and Filament Formation: Comparison with the Pipe Nebula 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 Gravitational Collapse and Filament Formation: Comparison with the Pipe Nebula, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gravitational Collapse and Filament Formation: Comparison with the Pipe Nebula will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-132281