TY - JOUR
T1 - A Milliarcsecond Localization Associates FRB 20190417A with a Compact Persistent Radio Source and an Extreme Magnetoionic Environment
AU - Moroianu, Alexandra M.
AU - Bhandari, Shivani
AU - Drout, Maria R.
AU - Hessels, Jason W. T.
AU - Hewitt, Dante M.
AU - Kirsten, Franz
AU - Marcote, Benito
AU - Pleunis, Ziggy
AU - Snelders, Mark P.
AU - Sridhar, Navin
AU - Bach, Uwe
AU - Bempong-Manful, Emmanuel K.
AU - Bezrukovs, Vladislavs
AU - Blaauw, Richard
AU - Bray, Justin D.
AU - Buttaccio, Salvatore
AU - Chatterjee, Shami
AU - Corongiu, Alessandro
AU - Feiler, Roman
AU - Gaensler, B. M.
AU - Gawronski, Marcin P.
AU - Giroletti, Marcello
AU - Ibik, Adaeze L.
AU - Karuppusamy, Ramesh
AU - Lazda, Mattias
AU - Leung, Calvin
AU - Lindqvist, Michael
AU - Masui, Kiyoshi W.
AU - Michilli, Daniele
AU - Nimmo, Kenzie
AU - Ould-Boukattine, Omar S.
AU - Pandhi, Ayush
AU - Paragi, Zsolt
AU - Pearlman, Aaron B.
AU - Puchalska, Weronika
AU - Scholz, Paul
AU - Shin, Kaitlyn
AU - Sluman, Jurjen J.
AU - Trudu, Matteo
AU - Williams-Baldwin, David
AU - Yang, Jun
PY - 2026/1/1
Y1 - 2026/1/1
N2 - We report the milliarcsecond localization of a high (∼1379 pc cm−3) dispersion measure (DM) repeating fast radio burst (FRB), FRB 20190417A. Combining European VLBI Network detections of five repeat bursts, we confirm the FRB’s host to be a low-metallicity, star-forming dwarf galaxy at z = 0.12817, similar to the hosts of FRB 20121102A, FRB 20190520B, and FRB 20240114A. We also confirm that it is associated with a previously reported persistent radio source (PRS), which is compact on milliarcsecond scales. Visibility-domain model fitting constrains the transverse physical size of the PRS to <23 pc and yields an integrated flux density of 190 ± 40 μJy at 1.4 GHz. Though we do not find significant evidence for DM evolution, FRB 20190417A exhibits a time-variable rotation measure (RM) ranging between +3958 ± 11 rad m−2 and +5061 ± 24 rad m−2 over a 50-day period. We find no evidence for intervening galaxy clusters in the FRB’s line of sight and place a conservative lower limit on the rest-frame host DM contribution of 1228 pc cm−3 (90% confidence)—the largest known for any FRB so far. This system strengthens the emerging picture of a rare subclass of repeating FRBs with large and variable RMs, above-average host DMs, and luminous PRS counterparts in metal-poor dwarf galaxies. Our results suggest that these systems are the result of environmental selection, or a distinct engine for FRB emission.
AB - We report the milliarcsecond localization of a high (∼1379 pc cm−3) dispersion measure (DM) repeating fast radio burst (FRB), FRB 20190417A. Combining European VLBI Network detections of five repeat bursts, we confirm the FRB’s host to be a low-metallicity, star-forming dwarf galaxy at z = 0.12817, similar to the hosts of FRB 20121102A, FRB 20190520B, and FRB 20240114A. We also confirm that it is associated with a previously reported persistent radio source (PRS), which is compact on milliarcsecond scales. Visibility-domain model fitting constrains the transverse physical size of the PRS to <23 pc and yields an integrated flux density of 190 ± 40 μJy at 1.4 GHz. Though we do not find significant evidence for DM evolution, FRB 20190417A exhibits a time-variable rotation measure (RM) ranging between +3958 ± 11 rad m−2 and +5061 ± 24 rad m−2 over a 50-day period. We find no evidence for intervening galaxy clusters in the FRB’s line of sight and place a conservative lower limit on the rest-frame host DM contribution of 1228 pc cm−3 (90% confidence)—the largest known for any FRB so far. This system strengthens the emerging picture of a rare subclass of repeating FRBs with large and variable RMs, above-average host DMs, and luminous PRS counterparts in metal-poor dwarf galaxies. Our results suggest that these systems are the result of environmental selection, or a distinct engine for FRB emission.
UR - https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=pure_starter&SrcAuth=WosAPI&KeyUT=WOS:001651534100001&DestLinkType=FullRecord&DestApp=WOS_CPL
U2 - 10.3847/2041-8213/ae28c7
DO - 10.3847/2041-8213/ae28c7
M3 - Article
SN - 2041-8205
VL - 996
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L16
ER -