A long-lived compact jet in the black hole X-ray binary candidate AT2019wey
Journal article, 2022
AT2019wey is a transient discovered by the Asteroid Terrestrial-impact Last Alert System survey in December of 2019. Follow-up optical, radio, and X-ray observations led to classification of this source as a Galactic black hole X-ray binary candidate. We carried out one-epoch 6.7 GHz European Very Long Baseline Interferometry Network and two-epoch multi-frequency (1.6, 4.5, 6.7 GHz) Very Long Baseline Array observations within a year after its discovery. These observations reveal a fading and flat-spectrum radio source with no discernible motion. These features suggest the detection of a compact jet. The source appears resolved at milliarcsecond scales, and the source angular size versus frequency trend is consistent with scatter broadening. This allows us to constrain the lower limit of the source distance to 6 kpc if the scattering medium is in a Galactic spiral arm. For a source location at greater than 3 kpc, the estimated upper limit of the peculiar velocity suggests the asymmetric natal kick may have occurred during the black hole formation stage.
Stars: individual: AT2019wey
X-rays: binaries
ISM: jets and outflows
Author
Hong Min Cao
Shangqiu Normal University
Giulia Migliori
Istituto di Radioastronomia
M. Giroletti
Istituto di Radioastronomia
Sándor Frey
Eötvös Loránd University (ELTE)
Hungarian Academy of Sciences
Jun Yang
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Krisztina E. Gabányi
Hungarian Academy of Sciences
Eötvös Loránd University (ELTE)
Lang Cui
Chinese Academy of Sciences
T. An
Shanghai Astronomical Observatory
X. Y. Hong
Shanghai Astronomical Observatory
Wen Da Zhang
Chinese Academy of Sciences
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 657 A104Subject Categories
Meteorology and Atmospheric Sciences
Astronomy, Astrophysics and Cosmology
Geophysics
DOI
10.1051/0004-6361/202142241