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This presentation by Julia Becker from Dortmund University explores the prediction of coincidence neutrino spectra from GRBs and compares them to average spectra. The talk includes an introduction to neutrino spectra, analysis of burst samples, and a comparison between coincidence and mean spectra. The findings suggest that even average spectra are not consistent with the predicted Waxman-Bahcall model.
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Prediction of Coincidence neutrino spectra from GRBs ...and a comparison to average spectra Julia Becker, Dortmund University March 22 2005 Julia Becker, Dortmund University
Overview • Short introduction to neutrino spectra • The diffuse spectrum • Burst samples: • Neutrino flux parameters • Coincidence and mean spectra • Summary Julia Becker, Dortmund University
The bigger picture Pendleton, G. et. al. Astrophysical Journal, (1999) Julia Becker, Dortmund University
GRB n Spectrum (I) e.g. Waxman/Bahcall, astro-ph/9807282 Julia Becker, Dortmund University
fe: fraction of electron to proton total energy 50%, 25% per particle fp: fraction of proton energy going into pions GRB n Spectrum (II) Julia Becker, Dortmund University
b-2 a The WB Spectrum b Waxman/Bahcall, astro-ph/9807282 Julia Becker, Dortmund University
Burst Samples • Variability: 568 bursts [Guetta et al.] • Lag: 292 bursts [Band et al.] • Subsample from variability sample: • 82 bursts within AMANDA field of view Julia Becker, Dortmund University
variability lag Neutrino-Parameters (I) Julia Becker, Dortmund University
variability lag Neutrino-Parameters (II) Julia Becker, Dortmund University
variability lag Neutrino-Parameter (III) Julia Becker, Dortmund University
e.g. 82 single burst spectra: Log(F E**2 /[GeV/s/sr/cm**2) Log(E/GeV) Julia Becker, Dortmund University
…and the coincidence spectrum Log(F E**2 /[GeV/s/sr/cm**2) Log(E/GeV) Julia Becker, Dortmund University
Comparison of mean and coincidence spectra Julia Becker, Dortmund University
Sample comparison Julia Becker, Dortmund University
Summary and Conculsions • Two different burst samples • Basic model of WB • Difference: Adjust parameters to single bursts • Result: • Samples differ from each other • Samples show different spectra than WB • Even average spectra are not consistent with WB Julia Becker, Dortmund University
The Future Julia Becker, Dortmund University
Upcoming internal report… • …preliminary version at app.uni-dortmund.de/~julia/ • …to be finalized about a week after Easter Julia Becker, Dortmund University