A Steadily Declining Dispersion Measure for the Repeating Fast Radio Burst FRB 20220529A: Evidence for a Fast Radio Burst Engine Embedded in an Expanding Supernova Remnant
Journal article, 2026
We present the discovery and subsequent 3.2 yr monitoring campaign of the repeating fast radio burst (FRB) FRB 20220529A with CHIME/FRB. We observe a gradual decline in dispersion measure (DM) of -0.881 +/- 0.001 pc cm-3 yr-1 (-1.235 +/- 0.001 pc cm-3 yr-1 in the rest frame), implying a >= 3.5% +/- 0.2% decrease in the total electron column in the source environment, and we see scattering timescale variations over weeks to years. We observe a short-lived excursion in which the DM rises by similar to 1 pc cm-3, immediately preceding an increase in transient Faraday rotation measure (RM) of similar to 2000 rad m-2 previously reported for this source, before returning to its gradual decline in DM. During this DM/RM excursion, we identify a local line-of-sight magnetic field of 3.4 +/- 0.2 mG around FRB 20220529A, corresponding to one of the most strongly magnetized FRB environments. We measure a decrease in the linear polarization fraction of FRB 20220529A bursts with decreasing frequency that we attribute to depolarization from multipath propagation in the source environment. We also place a 5 sigma upper limit on the spectral luminosity of an associated persistent radio source of <= 5 & times; 1028 erg s-1 Hz-1 at 1.5 GHz. These observations are consistent with FRB 20220529A originating from a young (approximately years to centuries old) expanding supernova remnant, with short-lived DM and RM variability arising from interactions with the supernova remnant or with a binary companion.
Author
[Person 7ceaf59b-5de5-4f45-8be1-07fe548a4b2a not found]
McGill University
University of Toronto
[Person af2bfe93-0ebc-4451-973d-af5ca60c4809 not found]
Northwestern Univ, Ctr Interdisciplinary Explorat & Res Astron, 1800 Sherman Ave
Massachusetts Institute of Technology (MIT)
[Person d7a731b1-63e8-4006-9e53-08058cc70d0d not found]
Massachusetts Institute of Technology (MIT)
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National Research Council Canada
[Person a7eb027f-c367-4108-af0b-704480f9012c not found]
Cornell University
[Person 82abab3a-c8eb-42c2-b714-e2aaf3e3fa1d not found]
McGill University
University of Amsterdam
[Person 18cf0683-3441-4896-b3e4-0240792a56d4 not found]
McGill University
University of Amsterdam
[Person e8893dba-1229-4fd3-890f-666ee24dfc27 not found]
University of California
University of Toronto
[Person d6fe73cb-8c39-42f1-9c0e-277a397b5362 not found]
Nicolaus Copernicus University (SGMK)
[Person 9fb01275-caab-451d-895c-a05ec58e61aa not found]
Netherlands Institute for Radio Astronomy (ASTRON)
McGill University
University of Amsterdam
[Person 6f669a70-46d3-4c78-bfa1-dd4d963f1ce7 not found]
McGill University
Tel Aviv University
[Person 1fed6e5c-f00e-44e7-9f8f-d06292ece9b6 not found]
McGill University
[Person 6f78622f-c371-4c1d-be54-6e01bb097bd0 not found]
Chalmers, Space, Earth and Environment, Onsala Space Observatory
[Person f9e8f957-8fae-40af-b9c7-0aa4a950f604 not found]
University of Toronto
[Person 136f7027-7e45-427b-b2db-cf26b400158a not found]
Miller Inst Basic Res, Stanley Hall, Room 206B
University of California
[Person ef15040e-7b8e-4dfb-b4e1-0b9da8e6bc17 not found]
McGill University
[Person 9aca9259-2f4c-4589-8bf2-7598cdc83d53 not found]
Massachusetts Institute of Technology (MIT)
[Person ce21125c-acfc-4fd2-b36d-3af400828851 not found]
McGill University
[Person 52e3bd4f-c850-46f8-b97c-ae307e40924a not found]
Aix Marseille University
[Person 79f842eb-ac3d-49d5-b830-15540e94074f not found]
McGill University
[Person abb3e06d-07ce-4454-a6fc-6df2eca1e65f not found]
University of Amsterdam
Netherlands Institute for Radio Astronomy (ASTRON)
[Person 75ceeee8-b8d4-4ce3-8b6b-7bb6900cd6df not found]
McGill University
Massachusetts Institute of Technology (MIT)
[Person f5e60fd1-dc5b-4c58-85a5-5612647222ad not found]
University of Amsterdam
Netherlands Institute for Radio Astronomy (ASTRON)
[Person 23268dbd-3b2f-4518-a69c-890d22f54984 not found]
National Aeronautics and Space Administration (NASA)
[Person 6e6e4b2e-f2b3-41ee-bca6-0e89db475121 not found]
McGill University
[Person 023d0ce0-ee16-416d-96ff-26eb6fa34d92 not found]
Nicolaus Copernicus University (SGMK)
[Person 0719a1a6-2e58-4678-9b38-d87a51777b51 not found]
McGill University
[Person 061120e9-1a71-4edb-939a-f833de4f0790 not found]
York University
[Person 7b726098-a46b-4ee1-87f2-bfae0fe61cfa not found]
McGill University
[Person 52852e0d-02a8-4b40-b32e-5965b60c93ef not found]
California Institute of Technology (Caltech)
[Person 26b387d4-6568-4c0f-a4ec-47df1389edf7 not found]
McGill University
Perimeter Institute for Theoretical Physics
[Person c5fe9cf0-9a5c-4372-aff3-faa87bc96a95 not found]
Perimeter Institute for Theoretical Physics
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 1000 2 L53Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
Meteorology and Atmospheric Sciences
DOI
10.3847/2041-8213/ae52f8