EMU detection of mysterious multiple component radio-continuum emission from nearby spiral Seyfert I type galaxy ‘Sand-timer’ (NGC 7213)
We present an Australian Square Kilometre Array Pathfinder (ASKAP) Evolutionary Map of the Universe (EMU) radio-continuum detection of the nearby spiral Seyfert I type galaxy NGC 7213 which we nickname ‘sand-timer’ due to its morphological appearance. We find an intriguing and peculiar emission extending from the central supermassive black hole (SMBH), which we refer to as galaxy hyperbubbles and/or active galactic nucleus (AGN) jets. Finally, we find two previously undetected kiloparsec-scale features in the polarised intensity image, which appear most likely also related to the central SMBH, as restarted bipolar radio jets, though somewhat obscured in the radio-continuum total intensity image. They resemble the bow shocks often seen in Fanaroff-Riley Class II (FR-II) radio galaxies, and so we propose they most likely represent an early episode of the ‘Sand-timer’s’ AGN jet activity. An alternative scenario is that the core of NGC 7213 may be a super massive binary black hole (SMBBH) which is undergoing a tidal disruption event (TDE), potentially causing the peculiar radio-continuum emission.
Authors
- R. Kothes (ORCID: https://orcid.org/0000-0001-5953-0100)
- E. Järvelä (ORCID: https://orcid.org/0000-0001-9194-7168)
- N. F. H. Tothill (ORCID: https://orcid.org/0000-0002-9931-5162)
- D. Leahy (ORCID: https://orcid.org/0000-0002-4814-958X)
- Zachary J. Smeaton (ORCID: https://orcid.org/0009-0009-7061-0553)
- J. Th. van Loon (ORCID: https://orcid.org/0000-0002-1272-3017)
- S. Shabala (ORCID: https://orcid.org/0000-0001-5064-0493)
- E. J. Crawford (ORCID: https://orcid.org/0000-0001-5197-1091)
- S. F. ur Rahman
- M. Selby (ORCID: https://orcid.org/0009-0002-2870-2971)
- B. S. Koribalski (ORCID: https://orcid.org/0000-0003-4351-993X)
- A. C. Bradley (ORCID: https://orcid.org/0009-0007-4802-2793)
- R. Z. E. Alsaberi (ORCID: https://orcid.org/0000-0001-5609-7372)
- G. L. White (ORCID: https://orcid.org/0000-0002-4914-6292)
- G. P. Rowell (ORCID: https://orcid.org/0000-0002-9516-1581)
- A. Ahmad (ORCID: https://orcid.org/0000-0002-0457-3661)
- M. D. Filipović (ORCID: https://orcid.org/0000-0002-4990-9288)
- E. J. Stanton (ORCID: https://orcid.org/0009-0004-0615-0779)
- D. Urosević (ORCID: https://orcid.org/0000-0003-0665-0939)
- V. Velović (ORCID: https://orcid.org/0000-0002-0416-3267)
- H. Sano
- S. Taziaux
- J. L. Payne (ORCID: https://orcid.org/0000-0001-6549-2454)
- A. M. Hopkins (ORCID: https://orcid.org/0000-0002-6097-2747)
- S. Lazarević (ORCID: https://orcid.org/0000-0001-6109-8548)
- C. Bordiu (ORCID: https://orcid.org/0000-0002-7703-0692)
- K. Tsuge (ORCID: https://orcid.org/0000-0002-2794-4840)
Institutions
- Texas Tech University (US)
- University of Tasmania (AU)
- Australia Telescope National Facility (AU)
- University of Calgary (CA)
- University of Karachi (PK)
- Dominion Astrophysical Observatory (CA)
- University of Belgrade (RS)
- Osservatorio Astrofisico di Catania (IT)
- Gifu University (JP)
- Keele University (GB)
- The University of Adelaide (AU)
- Western Sydney University (AU)
- National Institute for Astrophysics (IT)
- Ruhr University Bochum (DE)
- Macquarie University (AU)
Publication Details
- Journal
- The Open Journal of Astrophysics
- Published
- 2026-10-15
- DOI
- https://doi.org/10.33232/001c.172532
- Primary Topic
- Astrophysical Phenomena and Observations
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Science and Industry Endowment Fund
- Astronomy Australia Limited
- Australian Government
- Commonwealth Scientific and Industrial Research Organisation
- Curtin University of Technology
- Bulgarian Academy of Sciences
- Government of Western Australia
- Serbian Academy of Sciences and Arts