Abstract
Population III stars are theoretically expected to be prominent around redshifts z 20, consisting of mainly very massive stars (VMSs) with M∗ ≳ 100 M∀, but there is no direct observational evidence for these objects. They may produce collapsar gamma-ray bursts (GRBs), with jets driven by magnetohydrodynamic processes, whose total isotropicequivalent energy could be as high as Eiso ≳ 1057 erg over a cosmological-rest-frame duration of td ≳ 104 s, depending on the progenitor mass. The detection of a burst with such a high total energy and a long duration would be a strong evidence for a VMS progenitor. We calculate the prompt emission and afterglow spectra of such Pop. III GRBs based on the standard models, and show that they will be detectable with the Swift BAT/XRT and Fermi LAT instruments. We also show that the late-time radio afterglows of Pop. III GRBs for typical parameters, despite the large distances, can be very bright: ≃ 140 mJy at 1 GHz, which may lead to a constraint on the Pop. III GRB rate from the current radio survey data, and ≃ 2:4 mJy at 70 MHz, which implies that Pop. III GRB radio afterglows could be interesting background source candidates for 21 cm absorption line detections.
Original language | English (US) |
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Pages (from-to) | 76-81 |
Number of pages | 6 |
Journal | Memorie della Societa Astronomica Italiana, Supplementi - Journal of the Italian Astronomical Society, Supplement |
Volume | 21 |
State | Published - 2012 |
Event | GRBs as Probes: From the Progenitors Environment to the High - Como, Italy Duration: May 16 2011 → May 20 2011 |
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering
- Radiology Nuclear Medicine and imaging
- Astronomy and Astrophysics
- Instrumentation
- Atomic and Molecular Physics, and Optics