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It is now recognized that long-duration Gamma-Ray Bursts (GRBs) are linked to the collapse of massive stars, based on the association between (low-redshift) GRBs and (type Ic) core-collapse supernovae (SNe). The census of massive stars and GRBs reveals, however, that not all massive stars do produce a GRB. Only ~1% of core collapse SNe are able to produce a highly relativistic collimated outflow, and hence a GRB. The extra crucial parameter has long been suspected to be metallicity and/or rotation. We find observational evidence strongly supporting that both ingredients are necessary in order to make a GRB out of a core-collapsing star. A detailed study of the absorption pattern in the X-ray spectrum of GRB060218 reveals evidence of material highly enriched in low atomic number metals ejected before the SN/GRB explosion. We find that, within the current scenarios of stellar evolution, only a progenitor star characterized by a fast stellar rotation and sub-solar initial metallicity could produce such a metal enrichment in its close surrounding.
Gamma-ray bursts (GRBs) have been phenomenologically classified into long and short populations based on the observed bimodal distribution of duration. Multi-wavelength and multi-messenger observations in recent years have revealed that in general lo
We consider the production of charmed baryons and mesons in the proton-antiproton binary reactions at the energies of the future $bar{P}$ANDA experiment. To describe these processes in terms of hadronic interaction models, one needs strong couplings
We systematically analyze three GRB samples named as radio-loud, radio-quiet and radio-none afterglows, respectively. It is shown that dichotomy of the radio-loud afterglows is not necessary. Interestingly, we find that the intrinsic durations ($T_{i
Unsupervised pattern recognition algorithms support the existence of three gamma-ray burst classes; Class I (long, large fluence bursts of intermediate spectral hardness), Class II (short, small fluence, hard bursts), and Class III (soft bursts of in
Double neutron star (DNS) merger events are promosing candidates of short Gamma-ray Burst (sGRB) progenitors as well as high-frequecy gravitational wave (GW) emitters. On August 17, 2017, such a coinciding event was detected by both the LIGO-Virgo gr