Effects of neutrino degeneracy and of downscatter on neutrino radiation from dense stellar cores

Abstract

view Abstract Citations (8) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Effects of neutrino degeneracy and of downscatter of neutrino radiation from dense stellar cores. Lichtenstadt, I. ; Ron, A. ; Sack, N. ; Wagschal, J. J. ; Bludman, S. A. Abstract A simplified model is presented for several stages in the development of a neutronization shell in the inner core of a collapsing star. Neutrino degeneracy severely reduces neutrino emission and downscatter in energy, so that for all but the thinnest shell sources, surface emission of an approximately Fermi-Dirac neutrino spectrum obtains. The neutrino spectrum departs from exact Fermi-Dirac form only because of the outstreaming of low-energy neutrinos. Downscatter by electrons is helped by neutron scatterers present, but except for reducing the peak neutrino energy by about 30%, electrons play no dramatic part. The neutrino degeneracy inhibits downscatter so that the low-energy window in the Fermi-Dirac distribution leads to little neutrino loss. A simple equilibrium radiation picture emerges in which neutrinos are LTE thermally emitted in the neutronization shell and isotropically coherently scattered by neutrons and by nuclei on the way out of the overlying mantle. The Fermi statistics limit on neutrino flux is probably reached in practice, but is, in most cases, still insufficient for mantle blow-off. Publication: The Astrophysical Journal Pub Date: November 1978 DOI: 10.1086/156601 Bibcode: 1978ApJ...226..222L Keywords: Fermi-Dirac Statistics; Gravitational Collapse; Neutrinos; Stellar Cores; Stellar Radiation; Absorption Cross Sections; Degeneration; Scattering Cross Sections; Astrophysics; Collapsing Stars:Neutrinos; Neutrinos:Stellar Interiors full text sources ADS |