Proper Motion of the Neutron Star in the Supernova Remnant G18.9-1.1

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Holland-Ashford, Tyler, Williams, Brian, Slane, Patrick, Long, Xi
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912459912118272
author Holland-Ashford, Tyler
Williams, Brian
Slane, Patrick
Long, Xi
author_facet Holland-Ashford, Tyler
Williams, Brian
Slane, Patrick
Long, Xi
contents In this paper, we present the first direct measurement of the proper motion of the neutron star (NS) in the supernova remnant (SNR) G18.9-1.1 using a 15-year Chandra baseline. After correcting the observations' astrometric solutions using reference Gaia stars' positions, we measure a total proper motion of 24.7 $\pm$ 6.8 mas yr$^{-1}$ at an angle of $336^\circ \pm$ 16$^\circ$ east of north. Using the distance estimates from literature of 2.1 kpc and 3.8 kpc, this proper motion corresponds to Galactic rotation-corrected transverse velocities of 264d$_{2.1}$ $\pm$ 79 km s$^{-1}$ and 474d$_{3.8}$ $\pm$ 129 km s$^{-1}$, respectively. Our power ratio method analysis of SNR ejecta slightly favors the higher velocity, as multipole moments calculated from the back-evolved center using the farther distance are more consistent with values from other CCSNRs. The NS's motion is directly opposite the motion of bulk ejecta in G18.9$-$1.1, providing yet more evidence that NS kicks are generated via a conservation of momentum-like process between the NS and the ejecta, as has been observed in other SNRs.
format Preprint
id arxiv_https___arxiv_org_abs_2507_01084
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Proper Motion of the Neutron Star in the Supernova Remnant G18.9-1.1
Holland-Ashford, Tyler
Williams, Brian
Slane, Patrick
Long, Xi
High Energy Astrophysical Phenomena
In this paper, we present the first direct measurement of the proper motion of the neutron star (NS) in the supernova remnant (SNR) G18.9-1.1 using a 15-year Chandra baseline. After correcting the observations' astrometric solutions using reference Gaia stars' positions, we measure a total proper motion of 24.7 $\pm$ 6.8 mas yr$^{-1}$ at an angle of $336^\circ \pm$ 16$^\circ$ east of north. Using the distance estimates from literature of 2.1 kpc and 3.8 kpc, this proper motion corresponds to Galactic rotation-corrected transverse velocities of 264d$_{2.1}$ $\pm$ 79 km s$^{-1}$ and 474d$_{3.8}$ $\pm$ 129 km s$^{-1}$, respectively. Our power ratio method analysis of SNR ejecta slightly favors the higher velocity, as multipole moments calculated from the back-evolved center using the farther distance are more consistent with values from other CCSNRs. The NS's motion is directly opposite the motion of bulk ejecta in G18.9$-$1.1, providing yet more evidence that NS kicks are generated via a conservation of momentum-like process between the NS and the ejecta, as has been observed in other SNRs.
title Proper Motion of the Neutron Star in the Supernova Remnant G18.9-1.1
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2507.01084