Author: Daisuke Nakauchi
Abstract: Recent numerical simulations suggest that Population III (Pop III) stars have masses not larger than ∼ 100 MSun and typically ∼ 40 MSun. By self-consistently considering the jet generation from the central engine and its propagation in the envelope of these low-mass Pop III stars, we find that Pop III blue supergiant stars have the possibility to raise gamma-ray bursts (GRBs). We also investigate the observational characteristics and their detectability by future satellite missions like ``Lobster'' and ``EXIST'', assuming that the Ep - Lp (or Ep - Eiso) correlation holds for Pop III GRBs. If the Ep - Eiso correlation holds, we have the possibility to detect Pop III GRBs at z ∼ 9 as an ultra long duration X-ray rich GRB by "EXIST". Conversely, if the Ep - Lp correlation holds, we have the possibility to detect Pop III GRBs up to z ∼ 19 as an ultra long duration X-ray flash by "Lobster". We subsequently consider the thermal emission from the expanding cocoon, which stores injected energy from relativistic jets before the shock head breaks out the stellar surface. We predict that a Pop III GRB is associated with a luminous UV/optical/infrared transient, which is detectable up to z ∼ 15 in infrared bands years after the GRB by up-coming facilities like "JWST".