Astrophysical calibration of gravitational-wave detectors

TL;DR

This paper proposes a method to validate gravitational-wave detector calibration using gamma-ray bursts as standard sirens, enabling direct comparison of estimated and true luminosity distances to assess calibration accuracy.

Contribution

It introduces a novel calibration validation technique leveraging coincident gamma-ray bursts and gravitational-wave observations, providing a practical way to verify detector calibration.

Findings

Calibration can be confirmed within ~10% for sources within 100 Mpc.

Method is largely independent of current calibration procedures.

Calibration accuracy can be validated within ~20% up to 500 Mpc.

Abstract

We investigate a method to assess the validity of gravitational-wave detector calibration through the use of gamma-ray bursts as standard sirens. Such signals, as measured via gravitational-wave observations, provide an estimated luminosity distance that is subject to uncertainties in the calibration of the data. If a host galaxy is identified for a given source then its redshift can be combined with current knowledge of the cosmological parameters yielding the true luminosity distance. This will then allow a direct comparison with the estimated value and can validate the accuracy of the original calibration. We use simulations of individual detectable gravitational-wave signals from binary neutron star (BNS) or neutron star-black hole systems, which we assume to be found in coincidence with short gamma-ray bursts, to estimate any discrepancy in the overall scaling of the calibration for detectors in the Advanced LIGO and Advanced Virgo network. We find that the amplitude scaling of the calibration for the LIGO instruments could on average be confirmed to within $\sim 10\%$ for a BNS source within 100 Mpc. This result is largely independent of the current detector calibration method and gives an uncertainty that is competitive with that expected in the current calibration procedure. Confirmation of the calibration accuracy to within $\sim 20\%$ can be found with BNS sources out to $\sim 500$ Mpc.