Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-08-18
Astrophys.J. 615 (2004) 29-44
Astronomy and Astrophysics
Astrophysics
21 pages, 11 figures, Apj in press
Scientific paper
10.1086/423981
We investigate the interactions of high-redshift galaxy outflows with low-mass virialized (Tvir < 10,000K) clouds of primordial composition. While atomic cooling allows star formation in larger primordial objects, such "minihalos" are generally unable to form stars by themselves. However, the large population of high-redshift starburst galaxies may have induced widespread star formation in these objects, via shocks that caused intense cooling both through nonequilibrium H2 formation and metal-line emission. Using a simple analytic model, we show that the resulting star clusters naturally reproduce three key features of the observed population of halo globular clusters (GCs). First, the 10,000 K maximum virial temperature corresponds to the ~ 10^6 solar mass upper limit on the stellar mass of GCs. Secondly, the momentum imparted in such interactions is sufficient to strip the gas from its associated dark matter halo, explaining why GCs do not reside in dark matter potential wells. Finally, the mixing of ejected metals into the primordial gas is able to explain the ~ 0.1 dex homogeneity of stellar metallicities within a given GC, while at the same time allowing for a large spread in metallicity between different clusters. To study this possibility in detail, we use a simple 1D numerical model of turbulence transport to simulate mixing in cloud-outflow interactions. We find that as the shock shears across the side of the cloud, Kelvin-Helmholtz instabilities arise, which cause mixing of enriched material into > 20% of the cloud. Such estimates ignore the likely presence of large-scale vortices, however, which would further enhance turbulence generation. Thus quantitative mixing predictions must await more detailed numerical studies.
Harlow Francis
Scannapieco Evan
Weisheit Jon
No associations
LandOfFree
Triggering the Formation of Halo Globular Clusters with Galaxy Outflows 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 Triggering the Formation of Halo Globular Clusters with Galaxy Outflows, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Triggering the Formation of Halo Globular Clusters with Galaxy Outflows will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-83565