march 22 2005julia becker, dortmund university march 22 2005 prediction of coincidence neutrino...
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March 22 2005 Julia Becker, Dortmund University
Julia Becker, Dortmund University
March 22 2005
Prediction of Coincidence Prediction of Coincidence neutrino spectra from GRBsneutrino spectra from GRBs
...and a comparison to average spectra...and a comparison to average spectra
March 22 2005 Julia Becker, Dortmund University
Overview
I. Short introduction to neutrino spectraI. The diffuse spectrum
II. Burst samples:I. Neutrino flux parametersII. Coincidence and mean spectra
III. Summary
March 22 2005 Julia Becker, Dortmund University
The bigger picture
Pendleton, G. et. al. Astrophysical Journal, (1999)
March 22 2005 Julia Becker, Dortmund University
GRB Spectrum (I)
,
][]~,[
22
EdE
dnE
dE
dn
EkeVE tottot
b
b
E
E
E
E
dE
dNE
for
for 1
12
b
b
E
E
E
E
dE
dnE
for
for
1~ EEconstEEEEp
e.g. Waxman/Bahcall, astro-ph/9807282
March 22 2005 Julia Becker, Dortmund University
GRB Spectrum (II)
4
1
2
1/
][]~,[min
min
e
E
E
tottot
ffx
FxdEEdE
dn
EkeVE
f: fraction of proton energy going into pionsfe: fraction of electron to proton total energy per particle
March 22 2005 Julia Becker, Dortmund University
The WB Spectrum
b
s
'A
Waxman/Bahcall, astro-ph/9807282
March 22 2005 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
March 22 2005 Julia Becker, Dortmund University
Neutrino-Parameters (I)
variability
lag
March 22 2005 Julia Becker, Dortmund University
Neutrino-Parameters (II)
variability
lag
March 22 2005 Julia Becker, Dortmund University
Neutrino-Parameter (III)
variability
lag
March 22 2005 Julia Becker, Dortmund University
e.g. 82 single burst spectra:
Lo
g(
G
eV
/s/s
r/cm
**2
)
Log(E/GeV)
March 22 2005 Julia Becker, Dortmund University
…and the coincidence spectrum
Lo
g(
G
eV
/s/s
r/cm
**2
)
Log(E/GeV)
March 22 2005 Julia Becker, Dortmund University
Comparison of mean and coincidence spectra
March 22 2005 Julia Becker, Dortmund University
Sample comparison
March 22 2005 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
March 22 2005 Julia Becker, Dortmund University
The Future
March 22 2005 Julia Becker, Dortmund University
Upcoming internal report…
…preliminary version at
app.uni-dortmund.de/~julia/
…to be finalized about a week after Easter