Time-dependent visibility modelling of a relativistic jet in the X-ray binary MAXI J1803-298
Journal article, 2023
Tracking the motions of transient jets launched by low-mass X-ray binaries (LMXBs) is critical for determining the moment of jet ejection, and identifying any corresponding signatures in the accretion flow. However, these jets are often highly variable and can travel across the resolution element of an image within a single observation, violating a fundamental assumption of aperture synthesis. We present a novel approach in which we directly fit a single time-dependent model to the full set of interferometer visibilities, where we explicitly parametrize the motion and flux density variability of the emission components, to minimize the number of free parameters in the fit, while leveraging information from the full observation. This technique allows us to detect and characterize faint, fast-moving sources, for which the standard time binning technique is inadequate. We validate our technique with synthetic observations, before applying it to three Very Long Baseline Array (VLBA) observations of the black hole candidate LMXB MAXI J1803-298 during its 2021 outburst. We measured the proper motion of a discrete jet component to be 1.37 ± 0.14 mas h-1, and thus we infer an ejection date of MJD 59348.08+0.05-0.06, which occurs just after the peak of a radio flare observed by the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/Sub-Millimeter Array (ALMA), while MAXI J1803-298 was in the intermediate state. Further development of these new VLBI analysis techniques will lead to more precise measurements of jet ejection dates, which, combined with dense, simultaneous multiwavelength monitoring, will allow for clearer identification of jet ejection signatures in the accretion flow.
stars: jets
X-rays: binaries
stars: black holes
techniques: high angular resolution
techniques: interferometric
stars: individual: MAXI J1803-298
Author
C. M. Wood
International Centre for Radio Astronomy Research
J. C. A. Miller-Jones
International Centre for Radio Astronomy Research
A. Bahramian
International Centre for Radio Astronomy Research
Steven J. Tingay
International Centre for Radio Astronomy Research
T. Russell
Istituto nazionale di astrofisica (INAF)
Alexandra J. Tetarenko
East Asian Observatory
Texas Tech University
D. Altamirano
University of Southampton
Tomaso Belloni
Istituto nazionale di astrofisica (INAF)
F. Carotenuto
University of Oxford
Chiara Ceccobello
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
S. Corbel
The French Alternative Energies and Atomic Energy Commission (CEA)
M. Espinasse
The French Alternative Energies and Atomic Energy Commission (CEA)
R. P. Fender
University of Oxford
University of Cape Town
E. Körding
Radboud University
S. Migliari
University of Barcelona
European Space Agency (ESA)
David M. Russell
New York University Abu Dhabi
C. L. Sarazin
University of Virginia
G. R. Sivakoff
University of Alberta
Roberto Soria
The University of Sydney
Istituto nazionale di astrofisica (INAF)
Chinese Academy of Sciences
V. Tudose
Institute for Space Sciences, Bucharest
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 522 1 70-89Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
DOI
10.1093/mnras/stad939