General relativistic self-gravitating equilibrium disks around rotating neutron stars

TL;DR

This paper develops numerical models of rotating neutron stars with self-gravitating disks, emphasizing the importance of including disk self-gravity for accurate astrophysical simulations of neutron star systems.

Contribution

It extends the Komatsu-Eriguchi-Hachisu method to model massive, self-gravitating disks around neutron stars, providing new stationary solutions for astrophysical applications.

Findings

Self-gravity significantly affects disk structure.

Massive disks with up to solar masses modeled.

Solutions applicable to gravitational wave studies.

Abstract

In modeling a relativistic disk around a compact object, the self-gravity of the disk is often neglected while it needs to be incorporated for more accurate descriptions in several circumstances. Extending the Komatsu-Eriguchi-Hachisu self-consistent field method, we present numerical models of a rapidly rotating neutron star with a self-gravitating disk in stationary equilibrium. In particular, our approach allows us to obtain numerical solutions involving a massive disk with the rest mass $O(10^{-1})-O(10^0) M_\odot$ closely attached to a rotating neutron star. We also assess the impact of self-gravity on the internal structure of the disk and the neutron star. These axisymmetric, stationary solutions can be employed for simulations involving the neutron star-disk system in the context of high-energy transients and gravitational wave emissions.