Speaker
Mr
Jose Carpio
(Pennsylvania State University)
Description
We study high-energy neutrino production in collimated jets inside blue supergiant (BSG) progenitors of gamma-ray bursts (GRBs). Assuming
ultralong GRBs, cosmic ray acceleration and neutrino production at the point where collimation begins, we use a semi-analytic approach to
calculate the neutrino injection spectrum. These are then propagated through simulations, taking into account charged and neutral current
interactions with matter, to find the observed neutrino fluxes and flavor ratios on Earth. We observe a smooth transition in the flavor
ratio from 1:0.85:0.85 to 1:1.58:1.53 for injections close to the progenitor's edge in the 100TeV-1PeV region. For neutrino production
deeper in the progenitor, we find oscillations in the flavor ratio around the 1:1:1 mark for energies between 1TeV and 10TeV. This
behavior may be useful, in future neutrino detectors with precise flavor ratio measurements, to obtain information about the progenitor.
Assuming
typical values for ultralong GRB parameters, we see that jet luminosities $\sim 10^{45}$ erg s$^{-1}$ and uncollimated jet Lorentz factors
$\sim 50$ provide a good explanation to the IceCube event spectrum up to 1 PeV. Our method can be applied to quantitative tests of GRB
neutrinos and impact the allowed GRB parameter space.
Primary author
Mr
Jose Carpio
(Pennsylvania State University)
Co-author
Prof.
Kohta Murase
(Pennsylvania State University)
