The Distribution of Atomic Hydrogen in the Host Galaxies of FRBs
Journal article, 2025
We probe the atomic hydrogen (HI) emission from the host galaxies of fast radio bursts (FRBs) to investigate the emerging trend of disturbance and asymmetry in the population. Quadrupling the sample size, we detect 16 out of 17 new hosts in HI, with the single non-detection arising in a galaxy known to be transitioning towards quiescence. With respect to typical local Universe galaxies, FRB hosts are generally massive in HI (MHI > 109 M⊙), which aligns with previous studies reporting that FRB hosts also tend to have high stellar masses and are star-forming. However, they span a broad range of other HI derived properties. Using visual inspection alongside various asymmetry metrics, we identify six unambiguously settled host galaxies, demonstrating for the first time that a disturbed HI morphology is not a universal feature of FRB host galaxies. However, we find another six that show clear signs of disturbance, one borderline case, and three which require deeper or more targeted observations to reach a conclusion; this brings the confirmed ratio of disturbed-to-settled FRB hosts to 11:6. Given that roughly a 1:1 ratio is expected for random background galaxies of similar type, our observed ratio yields a p-value of 0.222. Therefore, we conclude that contrary to earlier indications, there is no statistically significant excess of HI disturbance in this sample of FRB host galaxies with respect to the general galaxy population, and hence we find no evidence for a fundamental connection between FRB progenitor formation and merger-induced star formation activity.
Author
H. Roxburgh
International Centre for Radio Astronomy Research
M. Glowacki
University of the Western Cape
International Centre for Radio Astronomy Research
University of Edinburgh
A. Bera
International Centre for Radio Astronomy Research
C. W. James
International Centre for Radio Astronomy Research
Nathan Deg
Queen's University
Q. Huang
Beijing University of Technology
K. Lee-Waddell
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
University of Western Australia
International Centre for Radio Astronomy Research
J. Wang
Beijing University of Technology
M. Caleb
The University of Sydney
A. Deller
Swinburne University of Technology
L. N. Driessen
The University of Sydney
Alexa C. Gordon
Northwestern University
Kelley Michelle Hess
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Netherlands Institute for Radio Astronomy (ASTRON)
J. Xavier Prochaska
University of Tokyo
National Astronomical Observatory of Japan
University of California
R.M. Shannon
Swinburne University of Technology
Y. Wang
Swinburne University of Technology
Z. Wang
International Centre for Radio Astronomy Research
D. Yang
Beijing University of Technology
Publications Astronomical Society of Australia
1323-3580 (ISSN) 1448-6083 (eISSN)
Vol. In PressSubject Categories (SSIF 2025)
Condensed Matter Physics
Astronomy, Astrophysics, and Cosmology
Meteorology and Atmospheric Sciences
DOI
10.1017/pasa.2025.10123