Prospects for Multimessenger Observations of Thorne-\.Zytkow Objects

TL;DR

This paper explores the potential for detecting Thorne-Zytkow objects through gravitational waves and electromagnetic signals, proposing models and identifying promising targets for current and future observatories.

Contribution

It introduces a model for gravitational wave detection of T.ZOs and assesses their detectability with Advanced LIGO and other gravitational wave detectors.

Findings

T.ZOs could be detectable with Advanced LIGO.

Certain targets are promising for joint optical and gravitational searches.

Detection of gravitational waves would confirm the neutron star core presence.

Abstract

Thorne-\.Zytkow objects (T\.ZOs) are a class of stellar object comprised of a neutron star core surrounded by a large and diffuse envelope. Their exterior appearance is identical to red supergiants; the distinctive electromagnetic signature of a T\.ZO is a suite of unusual chemical abundance patterns, including excesses of Li, Rb, Mo, and Ca. However, electromagnetic observations cannot unambiguously identify the presence of a neutron star core. Detection of continuous gravitational wave emission from a rotating neutron star core would provide strong supporting evidence for the existence of T\.ZOs. We present a model for gravitational wave detector confirmation of T\.ZOs and demonstrate that these objects should be detectable with Advanced LIGO. We also investigate possible targets for joint optical and gravitational searches, and comment on prospects for detectability in both current and future gravitational wave detector networks.