De-leptonization and Non-Axisymmetric Instabilities in Core Collapse Supernovae

Abstract

The timescale of de-leptonization by neutrino loss and associated contraction of a proto-neutron star is short compared to the time to progagate a shock through the helium core of a massive star, and so the de-leptonization phase does not occur in the vacuum of space, but within the supernova ambiance whether or not there has been a successful explosion. Dynamical non-axisymmetric instabilities (NAXI) are predicted for sufficiently strongly differentially rotating proto-neutron stars. Some modes are unstable for small values of the ratio of rotational kinetic energy to binding energy, T/|W| > 0.01. The NAXI are likely to drive magnetoacoustic waves into the surrounding time-dependent density structure. These waves represent a mechanism of the dissipation of the free energy of differential rotation of the proto-neutron star, and the outward deposition of this energy may play a role in the supernova explosion process. We estimate the power produced by this process and the associated timescale and discuss the possible systematics of the de-leptonization phase in this context. A likely possibility is that the proto-neutron star will spin down through these effects before de-leptonization and produce substantial but not excessive energy input.

15 pages, 1 figure, accepted for publication in the Astrophysical Journal

References in corpus (25)

• Rossby Wave Instability of Keplerian Accretion Disks
• Evolution of Protoneutron Stars
• The Magnetorotational Instability in Core Collapse Supernova Explosions
• Magnetar Spindown, Hyper-Energetic Supernovae, and Gamma Ray Bursts
• Rossby Wave Instability of Thin Accretion Disks -- II. Detailed Linear Theory
• Viscosity and Rotation in Core-Collapse Supernovae
• The Spin Periods and Rotational Profiles of Neutron Stars at Birth
• A non-spherical core in the explosion of supernova SN 2004dj
• R-Mode Oscillations in Rotating Magnetic Neutron Stars
• Dynamical Rotational Instability at Low $T/W$
• Three-dimensional simulations of stellar core collapse in full general relativity: Nonaxisymmetric dynamical instabilities
• One-armed Spiral Instability in a Low T/|W| Postbounce Supernova Core
• Broad Band Polarimetry of Supernovae: SN1994D, SN1994Y, SN1994ae, SN1995D and SN 1995H
• Dynamical bar-mode instability of differentially rotating stars: Effects of equations of state and velocity profiles
• The nature of low T/|W| dynamical instabilities in differentially rotating stars
• Unexpected Dynamical Instabilities In Differentially Rotating Neutron Stars
• Properties of r modes in rotating magnetic neutron stars. I. Kinematic Secular Effects and Magnetic Evolution Equations
• Properties of r modes in rotating magnetic neutron stars. II. Evolution of the r modes and stellar magnetic field
• Evolutionary sequences of rotating protoneutron stars
• Magnetic Helix Formation Driven by Keplerian Disk Rotation in an External Plasma Pressure --- The Initial Expansion Stage
• Nonlinear Development of the Secular Bar-mode Instability in Rotating Neutron Stars
• The Non-Monotonic Dependence of Supernova and Remnant Formation on Progenitor Rotation
• On Rapidly Rotating Magnetic Core-Collapse Supernovae
• The Secular Bar-Mode Instability in Rapidly Rotating Stars Revisited
• Extracting Rotational Energy in Supernova Progenitors: Transient Poynting Flux Growth vs. Turbulent Dissipation

Cited by in corpus (6)

• The Proto-Magnetar Model for Gamma-Ray Bursts
• Dimension as a Key to the Neutrino Mechanism of Core-Collapse Supernova Explosions
• Spectropolarimetry of the Type IIb Supernova 2001ig
• The Shape of Cas A
• Alfven Wave-Driven Supernova Explosion
• The Gravitational Wave Signature of Core-Collapse Supernovae