Spin evolution of a proto-neutron star

TL;DR

This paper models the early spin evolution of proto-neutron stars, considering neutrino-driven angular momentum loss, and predicts gravitational wave signals for detection by current and future detectors.

Contribution

It introduces a general relativistic model of proto-neutron star spin evolution including neutrino emission effects and gravitational wave emission estimates.

Findings

Rotation rate constrained by mass-shedding limit.

Predicted gravitational wave signals are potentially detectable.

Strict bounds on initial rotation rates are established.

Abstract

We study the evolution of the rotation rate of a proto-neutron star, born in a core-collapse supernova, in the first seconds of its life. During this phase, the star evolution can be described as a sequence of stationary configurations, which we determine by solving the neutrino transport and the stellar structure equations in general relativity. We include in our model the angular momentum loss due to neutrino emission. We find that the requirement of a rotation rate not exceeding the mass-shedding limit at the beginning of the evolution implies a strict bound on the rotation rate at later times. Moreover, assuming that the proto-neutron star is born with a finite ellipticity, we determine the emitted gravitational wave signal, and estimate its detectability by present and future ground-based interferometric detectors.