Investigating GW190425 with numerical-relativity simulations

TL;DR

This study uses numerical-relativity simulations to analyze GW190425, exploring how its non-detection of electromagnetic counterparts constrains the system's properties, especially the mass ratio and equation of state.

Contribution

The paper introduces new simulations of binary systems matching GW190425's parameters to assess the event's nature and implications for electromagnetic follow-up constraints.

Findings

GW190425 is incompatible with an unequal mass binary neutron star merger with q<0.8 under certain conditions.

Non-detection of kilonovae can help constrain the mass ratio of binary neutron star systems.

Simulations suggest the importance of detailed kilonova observations for future system parameter constraints.

Abstract

The third observing run of the LIGO-Virgo collaboration has resulted in about hundred gravitational-wave triggers including the binary neutron star merger GW190425. However, none of these events have been accompanied with an electromagnetic transient found during extensive follow-up searches. In this article, we perform new numerical-relativity simulations of binary neutron star and black hole - neutron star systems that have a chirp mass consistent with GW190425. Assuming that the GW190425's sky location was covered with sufficient accuracy during the electromagnetic follow-up searches, we investigate whether the non-detection of the kilonova is compatible with the source parameters estimated through the gravitational-wave analysis and how one can use this information to place constraints on the properties of the system. Our simulations suggest that GW190425 is incompatible with an unequal mass binary neutron star merger with a mass ratio $q<0.8$ when considering stiff or moderately stiff equations of state if the binary was face-on and covered by the observation. Our analysis shows that a detailed observational result for kilonovae will be useful to constrain the mass ratio of binary neutron stars in future events.