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THE DYNAMICAL AND THERMAL EVOLUTION OF MASSIVE STELLAR
CORE COLLAPSES THAT ``FIZZLE''
James N. Imamura
*
Institute of Theoretical Science and Department of
Physics
University of Oregon, Eugene, OR 97403
Institute of Theoretical Science and Department of
Physics
University of Oregon, Eugene, OR 97403
Core collapse in a rotating star may be arrested at
subnuclear density aborting a prompt supernova event,
if the core contains angular
momentum J >
1049 g cm2 s-1.
Because of the high electron fraction,
Ye = 0.4-0.49, and high entropy per baryon, Sb/k
~ 1-2, in the cores of massive stars,
fizzled collapses lead to secularly and
dynamically stable objects.
The post-collapse evolution is driven by
deleptonization which causes the fizzler to contract. The
fizzler spins-up as it contracts which may drive it to
dynamic instability in the barlike mode. It is this
possibility we address in our works.
The development of a barlike instability leads to a fizzler
composed of a central bar surrounded by an extensive set
of spiral arms. The evolution of the bar instability is
dominated by Newtonian self-interaction
gravitational torques between the bar and the spiral
arms, not by the gravitational radiation reaction torque.
Bars are thus not strong sources of gravitational
wave (GW) radiation. They radiate only
10-5-10-7
Mc2 in GWs per bar pattern period
with strains ~ 2x10-23 to 10-22
(for high-J and low-J fizzlers) at
distances of 15 Mpc for f = 100-300 Hz. The GW
radiation will be detectable by LIGO if bars can persist for
> 500-1,000 pattern periods.
*in collaboration with R. Durisen (Indiana University) &
B. Pickett (Purdue University, Calumet)
-
Core collapse in a rotating star may be arrested at
subnuclear density aborting a prompt supernova event,
if the core contains angular
momentum J >
1049 g cm2 s-1.
Because of the high electron fraction,
Ye = 0.4-0.49, and high entropy per baryon, Sb/k
~ 1-2, in the cores of massive stars,
fizzled collapses lead to secularly and
dynamically stable objects.
The post-collapse evolution is driven by
deleptonization which causes the fizzler to contract. The
fizzler spins-up as it contracts which may drive it to
dynamic instability in the barlike mode. It is this
possibility we address in our works.
The development of a barlike instability leads to a fizzler
composed of a central bar surrounded by an extensive set
of spiral arms. The evolution of the bar instability is
dominated by Newtonian self-interaction
gravitational torques between the bar and the spiral
arms, not by the gravitational radiation reaction torque.
Bars are thus not strong sources of gravitational
wave (GW) radiation. They radiate only
10-5-10-7
Mc2 in GWs per bar pattern period
with strains ~ 2x10-23 to 10-22
(for high-J and low-J fizzlers) at
distances of 15 Mpc for f = 100-300 Hz. The GW
radiation will be detectable by LIGO if bars can persist for
> 500-1,000 pattern periods.
*in collaboration with R. Durisen (Indiana University) & B. Pickett (Purdue University, Calumet)