Gamma-ray burst rate: high-redshift excess and its possible origins

Understand

Prompted by various analyses of long (Type II) GRB rates and their relationship to the cosmic star-formation history, metallicity and luminosity function evolution, we systematically analyze these effects with a Monte Carlo code.

• We test various cosmic star-formation history models including analytical and empirical models as well as those derived from cosmological simulations.
• We also explore expressions for metallicity enhancement of the GRB rate with redshift, as presented in the literature, and discuss improvements to these analytic expressions from the point of view of galactic evolution.
• These are also compared to cosmological simulations on metal enrichment.