The Delay of Population III Star Formation by Supersonic Streaming Velocities

Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

6 pages, 5 figures, accepted for publication in ApJ

Scientific paper

It has recently been demonstrated that coherent relative streaming velocities of order 30 km / s between dark matter and gas permeated the universe on scales below a few Mpc directly after recombination. We here use a series of high-resolution moving-mesh calculations to show that these supersonic motions significantly influence the virialization of the gas in minihalos, and delay the formation of the first stars. As the gas streams into minihalos with bulk velocities around 1 km / s at z ~ 20, the additional momentum and energy input reduces the gas fractions and central densities of the halos, increasing the typical virial mass required for efficient cooling by a factor of three, and delaying Population III star formation by dz ~ 4. Since the distribution of the magnitude of the streaming velocities is narrowly peaked around a non-negligible value, this effect is important in most regions of the universe. As a consequence, the increased minimum halo mass implies a reduction of the absolute number of minihalos that can be expected to cool and form Population III stars by up to an order of magnitude. We further find that the streaming velocities increase the turbulent velocity dispersion of the minihalo gas, which could affect its ability to fragment and hence alter the mass function of the first stars.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The Delay of Population III Star Formation by Supersonic Streaming Velocities 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 Delay of Population III Star Formation by Supersonic Streaming Velocities, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Delay of Population III Star Formation by Supersonic Streaming Velocities will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-552007

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.