Constraining the PopIII IMF with high-z GRBs
Abstract
We study the signatures of enrichment from PopIII stars in observations of PopII GRBs (GRBIIs) at high redshift by using numerical N-body/hydrodynamical simulations including atomic and molecular cooling, star formation and metal spreading from stellar populations with different initial mass functions (IMFs), yields and lifetimes. PopIII and PopII star formation regimes are followed simultaneously and both a top-heavy and a Salpeter-like IMF for pristine PopIII star formation are adopted. We find that the fraction of GRBIIs hosted in a medium previously enriched by PopIII stars (PopIII-dominated) is model-independent. Typical abundance ratios, such as [Si/O] versus[C/O] and [Fe/C] versus[Si/C], can help to disentangle enrichment from massive and intermediate PopIII stars, while low-mass first stars are degenerate with regular PopII generations. The properties of galaxies hosting PopIII-dominated GRBIIs are not very sensitive to the particular assumption on the mass of the first stars.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 2017
- DOI:
- 10.1093/mnras/stw3159
- arXiv:
- arXiv:1610.03594
- Bibcode:
- 2017MNRAS.466.1140M
- Keywords:
-
- gamma-ray burst: general;
- stars: Population III;
- cosmology: theory;
- dark ages;
- reionization;
- first stars;
- early Universe;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 9 pages, 4 figures