Proper Motion and Natal Kick in the Galactic Black Hole X-Ray Binary AT2019wey
Journal article, 2025
Understanding the formation mechanisms of stellar-mass black hole X-ray binaries (BHXBs) remains a fundamental challenge in astrophysics. The natal kick velocities imparted during black hole (BH) formation provide crucial constraints on these formation channels. In this work, we present a new-epoch very long baseline interferometry (VLBI) observation of the Galactic BHXB AT2019wey carried out in 2023. Combining with archival VLBI data from 2020, we successfully measure the proper motion of AT2019wey over a 3 yr timescale, namely, 0.78 ± 0.12 mas yr−1 in R.A. and −0.42 ± 0.07 mas yr−1 in decl. Employing the measured proper motion, we estimate its peculiar velocity and the potential kick velocity (PKV) through Monte Carlo simulations, incorporating uncertainties of its distance and radial velocity. The estimated PKV distributions and height above the Galactic plane suggest that AT2019wey’s BH likely formed through a supernova explosion rather than direct collapse.
Author
Lang Cui
Xinjiang Astronomical Observatory
Chinese Academy of Sciences
Pengfei Jiang
Xinjiang Astronomical Observatory
T. An
Chinese Academy of Sciences
Hong Min Cao
Shangqiu Normal University
Ning Chang
Xinjiang Astronomical Observatory
Giulia Migliori
Istituto di Radioastronomia
M. Giroletti
Istituto di Radioastronomia
S. Frey
Eötvös Loránd University (ELTE)
Hungarian Academy of Sciences
Research Centre For Astronomy and Earth Sciences
Jun Yang
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Krisztina E. Gabányi
Research Centre For Astronomy and Earth Sciences
Eötvös Loránd University (ELTE)
Hungarian Academy of Sciences
X. Y. Hong
Chinese Academy of Sciences
Wenda Zhang
Chinese Academy of Sciences
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 983 2 147Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.3847/1538-4357/adc0f7