English

Toward $ab\,initio$ extremely metal poor stars

Astrophysics of Galaxies 2016-09-21 v3

Abstract

Extremely metal poor stars have been the focus of much recent attention owing to the expectation that their chemical abundances can shed light on the metal and dust yields of the earliest supernovae. We present our most realistic simulation to date of the astrophysical pathway to the first metal enriched stars. We simulate the radiative and supernova hydrodynamic feedback of a 60M60\,M_\odot Population III star starting from cosmological initial conditions realizing Gaussian density fluctuations. We follow the gravitational hydrodynamics of the supernova remnant at high spatial resolution through its freely-expanding, adiabatic, and radiative phases, until gas, now metal-enriched, has resumed runaway gravitational collapse. Our findings are surprising: while the Population III progenitor exploded with a low energy of 1051erg10^{51}\,\text{erg} and injected an ample metal mass of 6M6\,M_\odot, the first cloud to collapse after the supernova explosion is a dense surviving primordial cloud on which the supernova blastwave deposited metals only superficially, in a thin, unresolved layer. The first metal-enriched stars can form at a very low metallicity, of only 25×104Z2-5\times10^{-4}\,Z_\odot, and can inherit the parent cloud's highly elliptical, radially extended orbit in the dark matter gravitational potential.

Keywords

Cite

@article{arxiv.1605.07236,
  title  = {Toward $ab\,initio$ extremely metal poor stars},
  author = {Jeremy S. Ritter and Chalence Safranek-Shrader and Milos Milosavljevic and Volker Bromm},
  journal= {arXiv preprint arXiv:1605.07236},
  year   = {2016}
}

Comments

11 pages, 7 figures, accepted for publication in MNRAS Sept 1, 2017

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