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Title: THE PHYSICS OF THE NEUTRINO MECHANISM OF CORE-COLLAPSE SUPERNOVAE

Journal Article · · Astrophysical Journal

Although it is known that the stalled accretion shock in models of core-collapse supernovae turns into explosion when the neutrino luminosity from the proto-neutron star (PNS) exceeds a critical value (L{sup crit}{sub {nu},core}) (the 'neutrino mechanism'), the physics of L{sup crit}{sub {nu},core} has never been systematically explored. We solve the accretion problem between the PNS surface and the accretion shock. We quantify the deep connection between the general problem of accretion flows with bounding shocks and the neutrino mechanism. In particular, we show that there is a maximum, critical sound speed above which the shock jump conditions cannot be satisfied and steady-state accretion is impossible. This physics is general and does not depend on a specific heating mechanism. For the simple model of pressure-less free fall onto a shock bounding an isothermal accretion flow, we show that shock solutions are possible only for sound speed c{sub T} < c{sup crit}{sub T} and that c{sup 2}{sub T}/v{sub esc}{sup 2} = 3/16 = 0.1875 at c{sup crit}{sub T}. We generalize this result to the supernova problem, showing that the same physics determines L{sup crit}{sub {nu},core}. The critical condition for explosion can be written as c{sup 2}{sub S}/v{sup 2}{sub esc} {approx_equal} 0.19, where c{sub S} is the adiabatic sound speed. This 'antesonic' condition describes L{sup crit}{sub {nu},core} over a broad range of parameters, and other criteria proposed in the literature fail to capture this physics. We show that the accretion luminosity reduces L{sup crit}{sub {nu},core} non-trivially. A larger PNS radius decreases L{sup crit}{sub {nu},core}, implying that a stiff high-density equation of state may be preferred. Finally, using an analytic model, we provide evidence that the reduction of L{sup crit}{sub {nu},core} seen in recent multi-dimensional simulations results from reduced cooling efficiency, rather than an increased heating rate.

OSTI ID:
22011757
Journal Information:
Astrophysical Journal, Vol. 746, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English