Abstract
We present the discovery of an as yet nonrepeating fast radio burst (FRB), FRB 20210117A, with the Australian Square Kilometre Array Pathfinder (ASKAP), as a part of the Commensal Real-time ASKAP Fast Transients Survey. The subarcsecond localization of the burst led to the identification of its host galaxy at z = 0.214(1). This redshift is much lower than what would be expected for a source dispersion measure (DM) of 729 pc cm−3, given typical contributions from the intergalactic medium and the host galaxy. Optical observations reveal the host to be a dwarf galaxy with little ongoing star formation—very different to the dwarf host galaxies of the known repeating FRBs 20121102A and 20190520B. We find an excess DM contribution from the host and attribute it to the FRB’s local environment. We do not find any radio emission from the FRB site or host galaxy. The low magnetized environment and the lack of a persistent radio source indicate that the FRB source is older than those found in other dwarf host galaxies, establishing the diversity of FRB sources in dwarf galaxy environments. We find our observations to be fully consistent with the “hypernebula” model, where the FRB is powered by an accretion jet from a hyperaccreting black hole. Finally, our high time resolution analysis reveals burst characteristics similar to those seen in repeating FRBs. We encourage follow-up observations of FRB 20210117A to establish any repeating nature.
| Original language | English (US) |
|---|---|
| Article number | 67 |
| Journal | Astrophysical Journal |
| Volume | 948 |
| Issue number | 1 |
| DOIs | |
| State | Published - May 1 2023 |
Funding
Based on observations collected at the European Southern Observatory under ESO program 0105.A-0687. The Australian Square Kilometre Array Pathfinder is part of the Australia Telescope National Facility, which is managed by CSIRO. The operation of ASKAP is funded by the Australian Government, with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Centre. The establishment of ASKAP, the Murchison Radio-astronomy Observatory, and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. We acknowledge the Wajarri Yamatji as the traditional owners of the Murchison Radio-astronomy Observatory site. The Australia Telescope Compact Array is part of the Australia Telescope National Facility, which is funded by the Australian Government for operation as a National Facility, managed by CSIRO. We acknowledge the Gomeroi people as the traditional owners of the Observatory site. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Access to the W. M. Keck Observatory was supported by Northwestern University and the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have had the opportunity to conduct observations from this mountain. S.B. would like to thank Elizabeth A. K. Adams, Reynier Peletier, Jason Hessels, and the Astroflash group for useful discussions. S.B. is supported by a Dutch Research Council (NWO) Veni Fellowship (VI.Veni.212.058). J.X.P., as a member of the Fast and Fortunate for FRB Follow-up team, acknowledges support from NSF grants AST-1911140, AST-1910471, and AST-2206490. K.W.B., J.P.M, and R.M.S. acknowledge Australian Research Council (ARC) grant DP180100857. R.M.S. acknowledges support through the Australian Research Council Future Fellowship FT190100155 and Discovery Project DP220102305. T.E. is supported by NASA, through the NASA Hubble Fellowship grant HST-HF2-51504.001-A, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. N.S. acknowledges support from NASA (grant No. 80NSSC22K0332), NASA FINESST (grant No. 80NSSC22K1597), and the Columbia University Dean\u2019s fellowship. C.W.J. and M.G. acknowledge support from the Australian Government, through the Australian Research Council\u2019s Discovery Projects funding scheme (project DP210102103). W.F. and A.C.G. acknowledge support from the National Science Foundation, under CAREER grant No. AST-2047919, and from the David and Lucile Packard Foundation.
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science