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arXiv · 2602.18436

Chandra Proper Motions and Milliarcsecond Astrometry of Nineteen Pulsars

Jack T. Dinsmore·Roger W. Romani
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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.

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Jack T. Dinsmore, Roger W. Romani. 2026-02-20. Chandra Proper Motions and Milliarcsecond Astrometry of Nineteen Pulsars. https://doi.org/10.3847/1538-4357/ae48eb

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