Gamma-ray bursts – sources of ultra-high-energy cosmic rays and neutrinos
Mauricio Bustamante (The Ohio State University)
Joel Jones (PUCP)
Fifty years after the first observation of ultra-high-energy cosmic rays (UHECRs), with energies of 10^19 eV and above, their origin remains unknown. Gamma-ray bursts (GRBs) are attractive possible culprits: short-lived, extremely luminous transient events occurring at cosmological distances, that are believed to be produced by relativistic jets of plasma ejected at the deaths of massive stars. The jets likely contain protons and nuclei, in addition to electrons and photons, which are accelerated up to the observed extreme energies (~ 10^21 eV). Proton-photon interactions inside the jet would produce UHE cosmic rays, photons, and neutrinos. I will introduce a general model of joint UHECR-neutrino emission that is capable of fitting current UHECR flux measurements. When, in addition, we enforce the present-day upper bounds on the GRB neutrino flux from IceCube, we are able to constrain large regions of the parameter space of the model: indeed, GRBs might be sources of UHE particles, but it is challenging that they are the dominant source class. Regardless, they are arguably the most promising target for UHE neutrino point source searches. Therefore, I will finalise by presenting a model of cosmic-ray, neutrino, and gamma-ray emission built up from multiple distinct collisions in a simulated GRB jet. From this, we derive a robust minimal neutrino flux that lies within the reach of future neutrino telescopes, and we show the need for multi-messenger studies of GRBs, and of other cosmic accelerators, in order to build an unbiased picture of the UHE sky.
– MB, P. Baerwald, K. Murase, and W. Winter, Accepted for publication in Nat. Comm., http://arxiv.org/abs/1409.2874
– P. Baerwald, MB, and W. Winter, Astropart. Phys. 62, 66 (2015), http://arxiv.org/abs/1401.1820
– P. Baerwald, MB, and W. Winter, Astrophys. J. 768, 186 (2013), http://arxiv.org/abs/1301.6163