Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-07-02
Astrophys.J.654:66-92,2006
Astronomy and Astrophysics
Astrophysics
Accepted by The Astrophysical Journal. Some minor changes. 65 pages, 3 tables, 21 figures (3 color). To appear in January 1, 2
Scientific paper
10.1086/509250
(abridged) We perform 12 extremely high resolution adaptive mesh refinement cosmological hydrodynamic simulations of Population III star formation in a Lambda CDM universe, varying the box size and large-scale structure, to understand systematic effects in the formation of primordial protostellar cores. We find results that are qualitatively similar to those observed previously. We observe that the threshold halo mass for formation of a Population III protostar does not evolve significantly with time in the redshift range studied (33 > z > 19) but exhibits substantial scatter due to different halo assembly histories: Halos which assembled more slowly develop cooling cores at lower mass than those that assemble more rapidly, in agreement with Yoshida et al. (2003). We do, however, observe significant evolution in the accretion rates of Population III protostars with redshift, with objects that form later having higher maximum accretion rates, with a variation of two orders of magnitude (10^-4 - 10^-2 Msolar/year). This can be explained by considering the evolving virial properties of the halos with redshift and the physics of molecular hydrogen formation at low densities. Our result implies that the mass distribution of Population III stars inferred from their accretion rates may be broader than previously thought, and may evolve with redshift. Finally, we observe that our collapsing protostellar cloud cores do not fragment, consistent with previous results, which suggests that Population III stars which form in halos of mass 10^5 - 10^6 Msun always form in isolation.
Norman Michael L.
O'Shea Brian W.
No associations
LandOfFree
Population III star formation in a Lambda CDM universe, I: The effect of formation redshift and environment on protostellar accretion rate 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 Population III star formation in a Lambda CDM universe, I: The effect of formation redshift and environment on protostellar accretion rate, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Population III star formation in a Lambda CDM universe, I: The effect of formation redshift and environment on protostellar accretion rate will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-451353