학술논문

Abundances and Transients from Neutron Star–White Dwarf Mergers
Document Type
article
Source
The Astrophysical Journal, Vol 956, Iss 2, p 71 (2023)
Subject
White dwarf stars
Neutron stars
Stellar accretion disks
Light curves
Gamma-ray bursts
Astrophysics
QB460-466
Language
English
ISSN
1538-4357
Abstract
We systematically investigate the mergers of neutron star–white dwarf binaries from beginning to end, with a focus on the properties of the inflows and outflows in accretion disks and their electromagnetic emissions. Using population synthesis models, we determine a subset of these binaries in which the white dwarf companion undergoes unstable mass transfer and complete tidal disruption, forming a large accretion disk around the neutron star. The material evolves according to a one-dimensional advection-dominated accretion-disk model with nuclear burning, neutrino emissions, and disk-surface wind ejection. The extreme dynamics of the entire process have proven difficult to analyze, and thus currently, the properties are poorly understood. The outflows from the mergers are iron- and nickel-rich, giving rise to optical and infrared emissions powered by the decay of the radioactive iron-type isotopes, calculated via the SuperNu light-curve code. We find these systems capable of powering bright, yet short-lived, optical transients with the potential to power gamma-ray bursts.