Measuring Mass and Radius of the Maximum-mass Nonrotating Neutron Star

TL;DR

This paper proposes a new gravitational-wave based method to precisely measure the maximum mass and radius of nonrotating neutron stars by analyzing black hole-neutron star merger remnants, aiding in understanding dense matter physics.

Contribution

It introduces a novel approach using third-generation gravitational-wave detectors to determine neutron star properties from black hole-neutron star merger remnants.

Findings

Potential to measure $M_{TOV}$ with 0.01 solar masses precision.

Potential to measure $R_{TOV}$ with 0.6 km precision.

Method applicable to ~100 detections for accurate constraints.

Abstract

The mass ($M_{\rm TOV}$) and radius ($R_{\rm TOV}$) of the maximum-mass nonrotating neutron star (NS) play a crucial role in constraining the elusive equation of state of cold dense matter and in predicting the fate of remnants from binary neutron star (BNS) mergers. In this study, we introduce a novel method to deduce these parameters by examining the mergers of second-generation (2G) black holes (BHs) with NSs. These 2G BHs are assumed to originate from supramassive neutron stars (SMNSs) formed in BNS mergers. Since the properties of the remnant BHs arising from the collapse of SMNSs follow a universal relation governed by $M_{\rm TOV}$ and $R_{\rm TOV}$, we anticipate that by analyzing a series ($\sim 100$ detections) of mass and spin measurements of the 2G BHs using the third-generation ground-based gravitational-wave detectors, $M_{\rm TOV}$ and $R_{\rm TOV}$ can be determined with a precision of $\sim 0.01M_\odot$ and $\sim 0.6$ km, respectively.