Milliarcsecond Localization of the Repeating FRB 20201124A
Journal article, 2022
Very long baseline interferometric (VLBI) localizations of repeating fast radio bursts (FRBs) have demonstrated a diversity of local environments: from nearby star-forming regions to globular clusters. Here we report the VLBI localization of FRB 20201124A using an ad hoc array of dishes that also participate in the European VLBI Network (EVN). In our campaign, we detected 18 bursts from FRB 20201124A at two separate epochs. By combining the visibilities from both epochs, we were able to localize FRB 20201124A with a 1 sigma uncertainty of 2.7 mas. We use the relatively large burst sample to investigate astrometric accuracy and find that for greater than or similar to 20 baselines (greater than or similar to 7 dishes) we can robustly reach milliarcsecond precision even using single-burst data sets. Subarcsecond precision is still possible for single bursts, even when only similar to 6 baselines (four dishes) are available. In such cases, the limited uv coverage for individual bursts results in very high side-lobe levels. Thus, in addition to the peak position from the dirty map, we also explore smoothing the structure in the dirty map by fitting Gaussian functions to the fringe pattern in order to constrain individual burst positions, which we find to be more reliable. Our VLBI work places FRB 20201124A 710 +/- 30 mas (1 sigma uncertainty) from the optical center of the host galaxy, consistent with originating from within the recently discovered extended radio structure associated with star formation in the host galaxy. Future high-resolution optical observations, e.g., with Hubble Space Telescope, can determine the proximity of FRB 20201124A's position to nearby knots of star formation.
Author
K. Nimmo
University of Amsterdam
Netherlands Institute for Radio Astronomy (ASTRON)
D. M. Hewitt
University of Amsterdam
J. W. T. Hessels
Netherlands Institute for Radio Astronomy (ASTRON)
University of Amsterdam
Franz Kirsten
Netherlands Institute for Radio Astronomy (ASTRON)
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
B. Marcote
Joint Institute for VLBI in Europe (JIVE)
U. Bach
Max Planck Society
R. Blaauw
Netherlands Institute for Radio Astronomy (ASTRON)
M. Burgay
Istituto nazionale di astrofisica (INAF)
A. Corongiu
Istituto nazionale di astrofisica (INAF)
R. Feiler
Nicolaus Copernicus University
M. P. Gawronski
Nicolaus Copernicus University
M. Giroletti
Istituto nazionale di astrofisica (INAF)
R. Karuppusamy
Max Planck Society
A. Keimpema
Joint Institute for VLBI in Europe (JIVE)
M. A. Kharinov
Russian Academy of Sciences
Michael Lindqvist
Chalmers, Space, Earth and Environment, Onsala Space Observatory
G. Maccaferri
Istituto nazionale di astrofisica (INAF)
A. Melnikov
Russian Academy of Sciences
A. Mikhailov
Russian Academy of Sciences
O. S. Ould-Boukattine
University of Amsterdam
Z. Paragi
Joint Institute for VLBI in Europe (JIVE)
M. Pilia
Istituto nazionale di astrofisica (INAF)
A. Possenti
Istituto nazionale di astrofisica (INAF)
M. P. Snelders
University of Amsterdam
G. Surcis
Istituto nazionale di astrofisica (INAF)
M. Trudu
Istituto nazionale di astrofisica (INAF)
T. Venturi
Istituto nazionale di astrofisica (INAF)
Wouter Vlemmings
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
N. Wang
Chinese Academy of Sciences
Jun Yang
Chalmers, Space, Earth and Environment, Onsala Space Observatory
J. Yuan
Chinese Academy of Sciences
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 927 1 L3Subject Categories
Astronomy, Astrophysics and Cosmology
Other Physics Topics
Geosciences, Multidisciplinary
DOI
10.3847/2041-8213/ac540f