Improving Distances to Binary Millisecond Pulsars with Gaia

TL;DR

This study enhances pulsar distance measurements by combining Gaia parallaxes with pulsar data, significantly improving accuracy and establishing criteria for reliable cross-matches in Gaia DR2 and DR3.

Contribution

It introduces a method to improve pulsar distances using Gaia data and evaluates the reliability of cross-matched binary companions.

Findings

Gaia DR3 parallaxes for pulsars improved by 53%

Pulsar distance estimates improved by 29%

Binary companions with <3.0σ detection are unreliable associations

Abstract

Pulsar distances are notoriously difficult to measure, and play an important role in many fundamental physics experiments, such as pulsar timing arrays (PTAs). Here we perform a cross-match between International PTA pulsars (IPTA) and Gaia's DR2 and DR3. We then combine the IPTA pulsar's parallax with its binary companion's parallax, found in Gaia, to improve the distance measurement to the binary. We find 7 cross-matched IPTA pulsars in Gaia DR2, and when using Gaia DR3, we find 6 IPTA pulsar cross-matches, but with 7 Gaia objects. Moving from Gaia DR2 to Gaia DR3, we find that the Gaia parallaxes for the successfully cross-matched pulsars improved by $53\%$, and pulsar distances improved by $29\%$. Finally, we find that binary companions with a $<3.0\sigma$ detection are unreliable associations, setting a high bar for successful cross-matches.