TYPE II SUPERNOVAE AND FIZZLERS
Normal stellar evolution: Main Sequence (core hydrogen burning)
===> Red Giant phase ===> helium core burning ===> Asymptotic Giant Branch
===> higher nuclear burning stages.
The normal nuclear lifetime of a star ends after its core has been converted to
iron-nickel. The Fe-Ni core has Mcore ~ 1.2-2 Mo
and Rcore ~ 1,000 km with Ye~0.4-0.49.
The inner core next collapses driven
by photodissociation and/or electron captures.
Inner core collapse halts when nuclear
density is reached, where the EOS stiffens.
A shock forms as the outer core settles onto the inner core.
The shock ejects
the envelope of the star leading to a Type II SN outburst.
Comment--for density > 1012 g cm-3,
the core is opaque to neutrinos; Ye freezes around 0.3-0.4.
For cores with J > 2x1049 g cm2 s-1, collapse
halts at sub-nuclear density because of centrifugal forces ===> Fizzler
The equilibrium fizzler deleptonizes ===> it contracts and spins-up.
At T/|W| ~ 0.27 (Ye~0.25), it encounters
the
bar-like dynamic instability.
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Normal stellar evolution: Main Sequence (core hydrogen burning) ===> Red Giant phase ===> helium core burning ===> Asymptotic Giant Branch ===> higher nuclear burning stages. The normal nuclear lifetime of a star ends after its core has been converted to iron-nickel. The Fe-Ni core has Mcore ~ 1.2-2 Mo and Rcore ~ 1,000 km with Ye~0.4-0.49. |
The inner core next collapses driven by photodissociation and/or electron captures.Inner core collapse halts when nuclear density is reached, where the EOS stiffens.A shock forms as the outer core settles onto the inner core. The shock ejects the envelope of the star leading to a Type II SN outburst. |
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The equilibrium fizzler deleptonizes ===> it contracts and spins-up. At T/|W| ~ 0.27 (Ye~0.25), it encounters the bar-like dynamic instability.