Astrometric Constraints on a Massive Black Hole Binary in NGC\,4472

TL;DR

This paper explores how next-generation Very Large Array (ngVLA) astrometric monitoring can detect and constrain massive black hole binaries in galaxies like NGC 4472, expanding the scope beyond previous studies focused on brighter targets.

Contribution

It demonstrates the potential of ngVLA to study fainter targets and test gravitational wave limits from pulsar timing arrays for massive black hole binaries.

Findings

ngVLA can effectively monitor mJy-level targets like NGC 4472.

Astrometric measurements can constrain black hole binary parameters.

The study extends previous methods to more numerous, fainter galaxies.

Abstract

In an EHT study of a Jy-level target, Safarzadeh et al. (2019) show how astrometric monitoring could constrain massive black hole binaries with the wide separations that make them long-lived against gravitational wave losses, and with the small mass ratios expected from merged satellite galaxies. With this ngVLA study, we show how such frontier topics could be explored for the more numerous mJy-level targets, such as NGC\,4472. We also discuss how ngVLA astrometric monitoring could test the upper limits from pulsar timing arrays on gravitational waves from NGC\,4472.