Chandra Proper Motions and Milliarcsecond Astrometry of Nineteen Pulsars

TL;DR

This paper reports highly precise X-ray proper motion measurements for 19 pulsars using Chandra data, leveraging Gaia-based alignment to improve astrometric accuracy and reveal new pulsar wind structures.

Contribution

It introduces an improved alignment method combining Gaia data with X-ray sources, achieving the most precise X-ray proper motions to date.

Findings

Detection of a new X-ray filament associated with a pulsar

Enhanced understanding of pulsar wind nebula structures

Proper motions with uncertainties as low as 1.3 mas/yr

Abstract

We present X-ray proper motion (PM) measurements of 19 pulsars using new and archival data from the Chandra X-ray Observatory, including pulsar wind trails and X-ray filaments. Precise X-ray PMs are often limited by uncertainties in aligning observations to a common reference frame. Our analysis uses unresolved X-ray flux from stars in the Gaia catalog in addition to X-ray bright point sources for alignment, improving uncertainties. We obtain absolute positions referenced to Gaia with typical astrometric precision $\sim$10 mas and PM statistical uncertainties down to 1.3 mas yr$^{-1}$, the most precise X-ray PM achieved to date. With our improved frame alignment, PM accuracies are now limited by the pulsar flux in most cases. These results reveal a new X-ray filament and illuminate the wind nebula structures and origins of several of these pulsars.