The initial stellar mass function from random sampling in hierarchical clouds II: statistical fluctuations and a mass dependence for starbirth positions and times

Details The initial stellar mass function from random sampling in hierarchical clouds II: statistical fluctuations and a mass dependence for starbirth positions and times The initial stellar mass function from random sampling in hierarchical clouds II: statistical fluctuations and a mass dependence for starbirth positions and times

1998-11-18

arxiv.org/abs/astro-ph/9811287v1

Astronomy and Astrophysics

Astrophysics

21 pages, 8 figures, scheduled for ApJ vol. 515, April 10, 1999

Scientific paper

10.1086/307011

Observed variations in the slope of the initial stellar mass function are shown to be consistent with a model in which the protostellar gas is randomly sampled from hierarchical clouds at a rate proportional to the square root of the local density. RMS variations in the IMF slope around the Salpeter value are +/- 0.4 when only 100 stars are observed, and +/- 0.1 when 1000 stars are observed. The hierarchical-sampling model also reproduces the tendency for massive stars to form closer to the center of a cloud, at a time somewhat later than the formation time of the lower mass stars. The assumed density dependence for the star formation rate is shown to be appropriate for turbulence compression, magnetic diffusion, gravitational collapse, and clump or wavepacket coalescence. The low mass flattening in the IMF comes from the inability of gas to form stars below the thermal Jeans mass at typical temperatures and pressures. Consideration of heating and cooling processes indicate why the thermal Jeans mass should be nearly constant in normal environments, and why it might increase in some starburst regions. The steep IMF in the extreme field is not explained by the model, but other origins are suggested.

Affiliated with

Also associated with

No associations

Rating

The initial stellar mass function from random sampling in hierarchical clouds II: statistical fluctuations and a mass dependence for starbirth positions and times 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 The initial stellar mass function from random sampling in hierarchical clouds II: statistical fluctuations and a mass dependence for starbirth positions and times, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The initial stellar mass function from random sampling in hierarchical clouds II: statistical fluctuations and a mass dependence for starbirth positions and times will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-481221