Multi-messenger Detection Rates and distributions of Binary Neutron Star Mergers and Their Cosmological Implications

TL;DR

This paper estimates the rates and distributions of binary neutron star mergers detectable through multi-messenger observations, highlighting their potential to constrain dark energy parameters in future gravitational-wave detector eras.

Contribution

It investigates multi-messenger detection rates and distributions of BNS mergers across different GW detector generations, incorporating models of sGRBs and afterglows, and assesses their cosmological implications.

Findings

Detection rates range from 300 to 3500 per year with advanced detectors.

Most events have redshifts below 2 and inclination angles under 20 degrees.

Potential constraints on dark energy parameters are estimated as Δw0 ≈ 0.02-0.05 and Δwa ≈ 0.1-0.4.

Abstract

The gravitational-wave (GW) events, produced by the coalescence of binary neutron-stars (BNS), can be treated as the standard sirens to probe the expansion history of the Universe, if their redshifts could be determined from the electromagnetic observations. For the high-redshift ($z\gtrsim 0.1$) events, the short $\gamma$-ray bursts (sGRBs) and the afterglows are always considered as the primary electromagnetic counterparts. In this paper, by investigating various models of sGRBs and afterglows, we discuss the rates and distributions of BNS mergers' multi-messenger observations with GW detectors in second-generation (2G), 2.5G, 3G era with the detectable sGRBs and the afterglows. For instance, for Cosmic Explorer GW detector, the rate is about (300-3500) per year with GECAM-like detector for $\gamma$-ray emissions and LSST/WFST detector for optical afterglows. In addition, we find these events have the redshifts $z\lesssim 2$ and the inclination angles $\iota\lesssim 20^{\circ}$. These results justify the rough estimation in previous works. Considering these events as standard sirens to constrain the equation-of-state parameters of dark energy $w_{0}$ and $w_{a}$, we obtain the potential constraints of $\Delta w_{0}\simeq 0.02-0.05$ and $\Delta w_{a}\simeq 0.1-0.4$.