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M. Olivo

Publications and source records attributed to M. Olivo.

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Neutrino emission from high-energy component gamma-ray bursts

Gamma-ray bursts have the potential to produce the particle energies (up to $10^{21}$ eV) and the energy budget ($10^{44} \rm{erg yr^{-1} Mpc^{-3}}$) to accommodate the spectrum of the highest energy cosmic rays; on the other hand, there is no observational evidence yet that they accelerate hadrons. Fermi recently observed two bursts that exhibit a power-law high-energy extension of the typical (Band) spectrum that extends to $\sim 30$ GeV. On the basis of fireball phenomenology we argue that they, along with GRB941017 observed by EGRET in 1994, show indirect evidence for considerable baryon loading. Since the detection of neutrinos is the only unambiguous way to establish that GRBs accelerate cosmic rays, we use two methods to estimate the neutrino flux produced when the baryons interact with fireball photons to produce charged pions and neutrinos. While the number of events expected from the Fermi bursts is small, we conclude that an event like GRB941017 will be detected by IceCube if gamma-ray bursts are indeed the sources of the cosmic rays.

astro-ph.HE

Prospects for GRB Science with the Fermi Large Area Telescope

The LAT instrument on the Fermi mission will reveal the rich spectral and temporal gamma-ray burst phenomena in the > 100 MeV band. The synergy with Fermi's GBM detectors will link these observations to those in the well explored 10-1000 keV range; the addition of the > 100 MeV band observations will resolve theoretical uncertainties about burst emission in both the prompt and afterglow phases. Trigger algorithms will be applied to the LAT data both onboard the spacecraft and on the ground. The sensitivity of these triggers will differ because of the available computing resources onboard and on the ground. Here we present the LAT's burst detection methodologies and the instrument's GRB capabilities.

astro-ph.HE