Extreme-mass-ratio burst detection with TianQin

TL;DR

This paper assesses TianQin's capability to detect extreme-mass-ratio bursts from black hole interactions, estimating detection rates, parameter uncertainties, and the impact of a network with LISA, concluding that TianQin can detect dozens of events with precise parameter estimation.

Contribution

It provides the first detailed analysis of TianQin's detection prospects for EMRBs, including event rates, parameter estimation accuracy, and background noise impact, especially considering a TianQin+LISA network.

Findings

TianQin can detect tens of EMRB events during its mission.

Parameter estimation for detected events can reach about 10% accuracy.

The gravitational wave background from unresolved EMRBs is negligible.

Abstract

The capture of compact objects by massive black holes in galaxies or dwarf galaxies will generate short gravitational wave signals, called extreme-mass-ratio bursts (EMRBs), before evolving into extreme-mass-ratio inspirals. Their detection will provide an investigation of the black hole properties and shed light on astronomy and astrophysics. In this work, we investigate the detection number of the TianQin observatory on EMRBs. Our result shows that TianQin can detect tens of EMRBs events during its mission lifetime. For those detected events, we use the Fisher information matrix to quantify these uncertainties in the inference of their parameters. We consider the possible network of TianQin+LISA and study how a network can improve parameter estimation. The result shows that, for most sources, the CO mass, the MBH mass, and the MBH spin can be determined with an accuracy of the order $10^{-1}$ and the sky localization can be determined with an accuracy of 10 square degrees. We further explore the gravitational wave background generated by those unsolved EMRBs and conclude that it is about $10^6$ times weaker than TianQin's sensitivity and thus it can be ignored.