Short-hard Gamma-Ray Bursts (SGRBs) are currently thought to arise from gravitational wave driven coalescences of double neutron star systems forming either in the field or dynamically in globular clusters. For both channels, we fit the peak flux distribution of BATSE SGRBs to derive the local burst formation rate and luminosity function. We then compare the resulting redshift distribution with Swift 2-yr data, showing that both formation channels are needed in order to reproduce the observations. Double neutron stars forming in globular clusters are found to dominate the distribution at z <~ 0.3, whereas the field population from primordial binaries can account for the high-z SGRBs. This result is not in contradiction with the observed host galaxy type of SGRBs.
Short Gamma-ray bursts: a bimodal origin?
GUIDORZI, Cristiano;
2008
Abstract
Short-hard Gamma-Ray Bursts (SGRBs) are currently thought to arise from gravitational wave driven coalescences of double neutron star systems forming either in the field or dynamically in globular clusters. For both channels, we fit the peak flux distribution of BATSE SGRBs to derive the local burst formation rate and luminosity function. We then compare the resulting redshift distribution with Swift 2-yr data, showing that both formation channels are needed in order to reproduce the observations. Double neutron stars forming in globular clusters are found to dominate the distribution at z <~ 0.3, whereas the field population from primordial binaries can account for the high-z SGRBs. This result is not in contradiction with the observed host galaxy type of SGRBs.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
