A magnetar parallax

Abstract

XTE J1810-197 (J1810) was the first magnetar identified to emit radio pulses, and has been extensively studied during a radio-bright phase in 2003$-$2008. It is estimated to be relatively nearby compared to other Galactic magnetars, and provides a useful prototype for the physics of high magnetic fields, magnetar velocities, and the plausible connection to extragalactic fast radio bursts. Upon the re-brightening of the magnetar at radio wavelengths in late 2018, we resumed an astrometric campaign on J1810 with the Very Long Baseline Array, and sampled 14 new positions of J1810 over 1.3 years. The phase calibration for the new observations was performed with two phase calibrators that are quasi-colinear on the sky with J1810, enabling substantial improvement of the resultant astrometric precision. Combining our new observations with two archival observations from 2006, we have refined the proper motion and reference position of the magnetar and have measured its annual geometric parallax, the first such measurement for a magnetar. The parallax of $0.40\pm 0.05$mas corresponds to a most probable distance $2.5_{-0.3}^{+0.4}$kpc for J1810. Our new astrometric results confirm an unremarkable transverse peculiar velocity of $\approx 200\mathrm{km}{\mathrm{s}}^{-1}$ for J1810, which is only at the average level among the pulsar population. The magnetar proper motion vector points back to the central region of a supernova remnant (SNR) at a compatible distance at $\approx 70$kyr ago, but a direct association is disfavored by the estimated SNR age of ~3 kyr.

10 pages, 3 figures, accepted for publication in MNRAS

References in corpus (15)

• Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
• Transient pulsed radio emission from a magnetar
• Discovery of 35 New Supernova Remnants in the Inner Galaxy
• Constraining the Neutron Star Mass-Radius Relation and Dense Matter Equation of State with NICER. I. The Millisecond Pulsar X-ray Data Set
• Implications of a "Fast Radio Burst" from a Galactic Magnetar
• Pulsar Parallaxes at 5 GHz with the Very Long Baseline Array
• Distances to Anomalous X-ray Pulsars using Red Clump Stars
• The UTMOST pulsar timing programme II: Timing noise across the pulsar population
• The Birthrate of Magnetars
• MultiView High Precision VLBI Astrometry at Low Frequencies
• Repeated, Delayed Torque Variations Following X-ray Flux Enhancements in the Magnetar 1E1048.1$-$5937
• Revisiting the birth locations of pulsars B1929+10, B2020+28,and B2021+51
• Energetics and Birth Rates of Supernova Remnants in the Large Magellanic Cloud
• Spin-down evolution and radio disappearance of the magnetar PSR J1622$-$4950
• Neutral Hydrogen Absorption Toward XTE J1810-197: the Distance to a Radio-Emitting Magnetar