A hot cocoon in the ultralong GRB 130925A: hints of a PopIII-like progenitor in a low density wind environment

Luigi Piro, Eleonora Troja, Bruce Gendre +7

GRB 130925A is a peculiar event characterized by an extremely long gamma-ray duration ($\approx$7 ks), as well as dramatic flaring in the X-rays for $\approx$20 ks. After this peri…