Radio Emission from Ultra-stripped Supernovae as Diagnostics for Properties of the Remnant Double Neutron Star Binaries

TL;DR

This paper investigates radio emissions from ultra-stripped supernovae to diagnose properties of the resulting double neutron star binaries, especially their merger potential within cosmic timescales, aiding observational strategies.

Contribution

It provides theoretical predictions of radio luminosities from ultra-stripped SNe based on stellar evolution models, linking radio signals to binary merger prospects.

Findings

High radio luminosity indicates small binary separation.

Radio emission can predict whether the DNS binary will merge within the cosmic age.

Results help optimize radio follow-up observation strategies.

Abstract

An ultra-stripped supernova (SN) is an explosion of a helium or C+O star whose outer envelope has been stripped away by a companion neutron star. A double neutron star (DNS) binary is believed to be left after the explosion, which will emit the gravitational wave later at the coalescence. Recent detections of a few candidates for the ultra-stripped SN have constrained the properties of the explosion and the progenitor, but little information is given as to whether the remnant DNS binary will merge within the cosmic age. A large fraction of the material stripped away from the helium star through the binary interaction is expected to escape from the system and form circumstellar material (CSM). The CSM should be traced by radio emission induced by the collision with the SN ejecta. Based on the stellar evolution models previously developed, we calculate the expected radio luminosities from ultra-stripped SNe. We find that high radio luminosity at its maximum can be an indicator of small separation of a DNS binary leading to its merger within the cosmic age. Our results can be used to optimize the strategy for the radio follow-up observations such as observational epochs and frequencies.