A Hyperactive Fast Radio Burst Pinpointed in an SMC-like Satellite Host Galaxy
Journal article, 2025

Precise localizations of fast radio bursts (FRBs) are essential for uncovering their host galaxies and immediate environments. We present the milliarcsecond-precision European VLBI Network localization of FRB 20240114A, a hyperactive repeating FRB, achieving ≲90 × 30 mas (1σ) accuracy. This precision places the burst 0.5 kpc from the nucleus of its low-metallicity star-forming dwarf host at a spectroscopic redshift of z = 0.130287. Our Gran Telescopio CANARIAS spectroscopic follow-up reveals that the dwarf FRB host is gravitationally bound to a more massive, star-forming spiral galaxy. This establishes the first known instance of an FRB residing in a satellite galaxy within a larger galactic system. This configuration, analogous to the Small Magellanic Cloud orbiting the Milky Way (but at a lower overall mass scale), expands the known diversity of FRB host environments and offers important insights for interpreting seemingly “hostless” or highly offset FRBs. Furthermore, our detailed dispersion measure (DM) budget analysis indicates that the dominant contribution to FRB 20240114A’s DM likely originates from the foreground galaxy halos. This finding addresses the anomalously high DM observed for this FRB and underscores the significant role of intervening foreground structures in shaping observed FRB DMs, which is important for accurate FRB-based cosmological measurements. Our results highlight the importance of deep, high-resolution optical/infrared observations (e.g., with the Hubble or James Webb Space Telescopes) to fully leverage our precise radio localization and probe the immediate astrophysical birthplaces of FRB progenitors within these complex galactic systems.

Author

M. Bhardwaj

Carnegie Mellon University (CMU)

M. P. Snelders

Netherlands Institute for Radio Astronomy (ASTRON)

Anton Pannekoek Institute for Astronomy

J. W. T. Hessels

McGill University

Netherlands Institute for Radio Astronomy (ASTRON)

Anton Pannekoek Institute for Astronomy

A. Gil De Paz

IPARCOS-UCM (Instituto de Física de Partículas y del Cosmos)

Complutense University

Shivani Bhandari

Commonwealth Scientific and Industrial Research Organisation (CSIRO)

B. Marcote

Netherlands Institute for Radio Astronomy (ASTRON)

Joint Institute for Very Long Baseline Interferometry European Research Infrastructure Consortium (JIVE)

Aida Kirichenko

Universidad Nacional Autónoma de México

O. S. Ould-Boukattine

Netherlands Institute for Radio Astronomy (ASTRON)

Anton Pannekoek Institute for Astronomy

Franz Kirsten

Chalmers, Space, Earth and Environment, Onsala Space Observatory

Netherlands Institute for Radio Astronomy (ASTRON)

Emmanuel K. Bempong-Manful

University of Manchester

University of Bristol

V. Bezrukovs

Ventspils Augstskola

Justin D. Bray

University of Manchester

S. Buttaccio

Istituto di Radioastronomia

Istituto nazionale di astrofisica (INAF)

A. Corongiu

Istituto nazionale di astrofisica (INAF)

R. Feiler

Nicolaus Copernicus University (SGMK)

M. P. Gawroński

Nicolaus Copernicus University (SGMK)

Anton Pannekoek Institute for Astronomy

M. Giroletti

Istituto di Radioastronomia

Danté M. Hewitt

Anton Pannekoek Institute for Astronomy

Michael Lindqvist

Chalmers, Space, Earth and Environment, Onsala Space Observatory

G. Maccaferri

Istituto di Radioastronomia

A. Moroianu

Anton Pannekoek Institute for Astronomy

K. Nimmo

Massachusetts Institute of Technology (MIT)

Z. Paragi

Joint Institute for Very Long Baseline Interferometry European Research Infrastructure Consortium (JIVE)

W. Puchalska

Nicolaus Copernicus University (SGMK)

N. Wang

Xinjiang Astronomical Observatory

David Williams-Baldwin

University of Manchester

J. P. Yuan

Xinjiang Astronomical Observatory

Astrophysical Journal Letters

2041-8205 (ISSN) 2041-8213 (eISSN)

Vol. 992 2 L35

Onsala space observatory infrastructure

Swedish Research Council (VR) (2017-00648), 2018-01-01 -- 2021-12-31.

Subject Categories (SSIF 2025)

Astronomy, Astrophysics, and Cosmology

Meteorology and Atmospheric Sciences

DOI

10.3847/2041-8213/ae0b68

More information

Latest update

10/31/2025