presupernovae as powerful neutrino sources
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Presupernovae as powerful neutrino sources
detectable by next neutrino experiments
M. Kutschera, A. Odrzywołek, M. Misiaszek
Ustroń 2009
• Neutrino astrophysics group• Institute of Physics, Jagellonian
University, Kraków, Poland:A.Odrzywołek, M. Misiaszek, M.K.
References to our papers: arXivNeutrino spectra available at
• Research summary:• Spectra of neutrinos from stars at late stages
of thermonuclear burning (presupernovae) are found
• This allows us to predict counting rates in various neutrino detectors
• Presupernovae seem to be detectable by next generation of neutrino detectors
• Stars with initial mass (ZAMS) M>9Msol
after red giant phase:– ignite carbon– develope iron core – end life as core-collapse supernovae– example: 15 Msol :
Nearby candidate:
- Betelgeuse in ORION constellation
- distance 130 pc
• After carbon ignition neutrino-cooled stars• Photon luminosity much less L<<Lν
than neutrino luminosity.-photon luminosity constant after carbon ignition-neutrino luminosity grows by many orders!
Strong temperature growth in the core
Can neutrino experiments detect presupernovae?
• Pair annihilation dominant• Antineutrino flux from pair annihilation crucial !• Different than for the Sun (only neutrinos)
High density – neutrino and antineutrino spectra differ
• Near the collapse:– Total flux grows as Lν ~Tc
9
– Mean neutrino energy grows
Predictions for various detectors
• Range one day before collapse (various detectors)
Presupernova neutrinos vs geoneutrinos
• Nuclear reactions produce more neutrinos νe
than pair annihilation • More than 1000 nuclei must be included
Weak nuclear reactions: neutrinos excess
Comparison with solar neutrinos
REAL NEUTRINO ASTRONOMY
STARTS
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