Physical Mechanism for the Intermediate Characteristic Stellar Mass in the Extremely Metal-poor Environments

Details Physical Mechanism for the Intermediate Characteristic Stellar Mass in the Extremely Metal-poor Environments Physical Mechanism for the Intermediate Characteristic Stellar Mass in the Extremely Metal-poor Environments

2008-02-07

arxiv.org/abs/0802.0943v1

Astronomy and Astrophysics

Astrophysics

4 pages, 3 figures, ApJ Letters in press

Scientific paper

10.1086/587035

If a significant fraction of metals is in dust, star-forming cores with metallicity higher than a critical value ~10^{-6}-10^{-5}Z_sun are able to fragment by dust cooling, thereby producing low-mass cores. Despite being above the critical metallicity, a metallicity range is found to exist around 10^{-5}-10^{-4}Z_sun where low-mass fragmentation is prohibited. In this range, three-body H_2 formation starts at low (~100K) temperature and thus the resulting heating causes a dramatic temperature jump, which makes the central part of the star-forming core transiently hydrostatic and thus highly spherical. With little elongation, the core does not experience fragmentation in the subsequent dust-cooling phase. The minimum fragmentation mass is set by the Jeans mass just before the H_2 formation heating, and its value can be as high as ~10M_sun. For metallicity higher than ~10^{-4}Z_sun, H_2 formation is almost completed by the dust-surface reaction before the onset of the three-body reaction, and low-mass star formation becomes possible. This mechanism might explain the higher characteristic mass of metal-poor stars than in the solar neighborhood presumed from the statistics of carbon-enhanced stars.

Affiliated with

Also associated with

No associations

Rating

Physical Mechanism for the Intermediate Characteristic Stellar Mass in the Extremely Metal-poor Environments 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 Physical Mechanism for the Intermediate Characteristic Stellar Mass in the Extremely Metal-poor Environments, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Physical Mechanism for the Intermediate Characteristic Stellar Mass in the Extremely Metal-poor Environments will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-364553