Stars as Laboratories for Fundamental Physics - MPP Theory Group

412 Chapter 11
bounce accretion, and the temperature profile of the core after collapse.
As expected, a soft EOS leads to a large amount of binding energy
and thus to large integrated neutrino luminosities; a large core mass
or large postbounce accretion rate has a similar effect. A soft EOS
leads to relatively high temperatures during deleptonization, causing
large neutrino opacities and thus long emission time scales. If the EOS
is too soft, or the core mass too large, the final configuration is not
stable and collapses, presumably to a black hole. This must not occur
too early to avoid conflict with the duration of the observed SN 1987A
Fig. 11.7. Luminosity and temperature of the ν e flux from the protoneutron
star model 55 of Burrows (1988) which is based on a “stiff equation of state,”
an initial baryonic core mass of 1.3 M ⊙ , and an accretion of 0.2 M ⊙ within
the first 0.5 s. The dotted line in the upper panel indicates a t −1 behavior,
in the lower panel it indicates e −t/4τ with τ ≈ 10 s. The neutrino spectral
distribution was taken to be thermal.