The First Billion Years project: gamma-ray bursts at z>5

Understand

Long gamma-ray burst's (LGRB's) association to the death of massive stars suggest they could be used to probe the cosmic star formation history (CSFH) with high accuracy, due to their high luminosities.

• We utilise cosmological simulations from the First Billion Years project to investigate the biases between the CSFH and the LGRB rate at z>5, assuming various different models and constraints on the progenitors of LGRBs.
• We populate LGRBs using a selection based on environmental properties and demonstrate that the LGRB rate should trace the CSFH to high redshifts.
• The measured LGRB rate suggests that LGRBs have opening angles of theta_jet=0.1 deg, although the degeneracy with the progenitor model cannot rule out an underlying bias.