Solid lines: Spectra of ﹩\nu _{e}\,\overline{\nu }_{e}﹩ (upper) and ﹩\nu _{\mu }\,\overline{\nu }_{\mu }﹩ (or ﹩\nu _{\tau }\,\overline{\nu }_{\tau }﹩; lower) emission due to e⁺e⁻ annihilation during the collapse of a supermassive star with an assumed core temperature T = 1.5 MeV. The dotted line is the analytical fit to the ﹩\nu _{e}\,\overline{\nu }_{e}﹩ spectrum. A common arbitrary normalization applies to all curves.