English

First supernovae in dwarf protogalaxies

Astrophysics 2009-11-13 v1

Abstract

(Abridged) We explore numerically the chemical, thermal, and dynamical evolution of a shell formed by a high-energy supernova explosion (105310^{53} erg) in dwarf protogalaxies with total mass 107M10^7 M_\odot at a redshift z=12z=12. We consider two initial configurations for the baryonic matter, one without rotation and the other having the ratio of rotational to gravitational energy β=0.17\beta=0.17. The (non-rotating) dark matter halo is described by a quasi-isothermal sphere. We find that the dynamics of the shell is different in protogalaxies with and without rotation. For instance, the Rayleigh-Taylor instability in the shell develops faster in protogalaxies without rotation. The fraction of a blown-away baryonic mass is approximately twice as large in models with rotation (20\sim 20%) than in models without rotation. On the other hand, the chemical evolution of gas in protogalaxies with and without rotation is found to be similar. The relative number densities of molecular hydrogen and HD molecules in the cold gas (T103T \le 10^3 K) saturate at typical values of 10310^{-3} and 10710^{-7}, respectively. The clumps formed in the fragmented shell move with velocities that are at least twice as large as the escape velocity. The mass of the clumps is 0.110\msun\sim 0.1-10 \msun, which is lower than the Jeans mass. We conclude that the clumps are pressure supported. A supernova explosion with energy 105310^{53} ergs destructs our model protogalaxy. The clumps formed in the fragmented shell are pressure supported. We conclude that protogalaxies with total mass 107M\sim 10^{7} M_\odot are unlikely to form stars due to high-energy supernova explosions of the first stars.

Keywords

Cite

@article{arxiv.0807.3414,
  title  = {First supernovae in dwarf protogalaxies},
  author = {E. O. Vasiliev and E. I. Vorobyov and Yu. A. Shchekinov},
  journal= {arXiv preprint arXiv:0807.3414},
  year   = {2009}
}

Comments

12 pages, 8 figures, accepted in A&A

R2 v1 2026-06-21T11:02:59.614Z