We propose a new parameterization of the antineutrino flux from core collapse supernovae, that allows an interpretation of its astrophysical parameters within the Bethe and Wilson scenario for the explosion, and that leads to a reasonable (smooth) behavior of the average energy and of the luminosity curve. We apply it to analyze the events observed by Kamiokande-II, IMB and Baksan detectors in correlation with SN1987A. For the first time, we consider in the same analysis all data characteristics: times, energies and angles of the observed events. We account for the presence of background and evaluate the impact of neutrino oscillations. The hypothesis that the initial luminous phase of emission (accretion) is absent can be rejected at the 2 % significance level. Without the need to impose external priors in the likelihood analysis, the best-fit values of the astrophysical parameters are found to be in remarkable agreement with the expectations of the standard core-collapse scenario; in particular, the electron antineutrino-sphere radius is 16 km, the duration of the accretion phase is found to be 0.55 s, and the initial accreting mass is 0.22 M(sun). Similarly the total energy emitted in neutrinos is 2.2*10^{53} erg, again close to the expectations. The errors on the parameters are evaluated and found to be relatively large, consistently with the limited number of detected events; the two dimensional confidence regions, that demonstrate the main correlations between the parameters, are also given.Comment: 15 pages, 5 figure

We consider the impact of oscillations on 1-200 TeV neutrinos expected from RX J1713.7-3946. After a description of the nature of the source, we obtain a prediction for the neutrino fluxes, based on the intense gamma ray flux first seen by CANGAROO and recently measured by H.E.S.S. experiment. We study the effect of 3 flavor oscillations in detail and consider the impact on the muon flux induced by these high energy neutrinos, potentially observable by a neutrino telescope located in the Northern hemisphere. A detector in the Mediterranean with an effective area of 1 km 2 and unit detection efficiency should be able to see a signal of about 10 muons per year.

We reanalyze the neutrino events from SN1987A in IMB and Kamiokande-II ͑KII͒ detectors, and compare them with the expectations from simple theoretical models of the neutrino emission. In both detectors the angular distributions are peaked in the forward direction, and the average cosines are 2 sigma above the expected values. Furthermore, the average energy in KII is low if compared with the expectations; but, as we show, the assumption that a few ͑probably one͒ events at KII have been caused by elastic scattering is not in contrast with the ''standard'' picture of the collapse and yields more satisfactory distributions in angle and ͑marginally͒ in energy. The observations give useful information on the astrophysical parameters of the collapse. We find that the mean energy of electron antineutrinos is ͗E͘ϭ12-15 MeV, the total energy radiated around (2 -5)ϫ10 53 erg, and there is a hint for a relatively large radiation of nonelectronic neutrino species. These properties of the neutrino burst are not in disagreement with those suggested by the current theoretical paradigm, but the data leave wide space to nonstandard pictures, especially when neutrino oscillations are included.