EMU detection of mysterious multiple component radio-continuum emission from nearby spiral Seyfert I type galaxy 'Sand-timer' (NGC 7213)
Abstract
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 intriguing, 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 supermassive binary black hole (SMBBH) undergoing a tidal disruption event (TDE), potentially causing the peculiar radio-continuum emission.
Versions
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BibTeX
@misc{filipovic2026detection,
title = {{EMU detection of mysterious multiple component radio-continuum emission from nearby spiral Seyfert I type galaxy 'Sand-timer' (NGC 7213)}},
author = {M. D. Filipović and Z. J. Smeaton and B. S. Koribalski and R. Kothes and A. Ahmad and R. Z. E. Alsaberi and C. Bordiu and A. C. Bradley and E. J. Crawford and A. M. Hopkins and E. Järvelä and S. Lazarević and D. Leahy and J. L. Payne and S. F. ur Rahman and G. P. Rowell and H. Sano and M. Selby and S. S. Shabala and E. J. Stanton and S. Taziaux and K. Tsuge and D. Urosević and N. F. H. Tothill and J. Th. van Loon and V. Velović and G. L. White},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.18285},
eprint = {2610.18285},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.18285},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - EMU detection of mysterious multiple component radio-continuum emission from nearby spiral Seyfert I type galaxy 'Sand-timer' (NGC 7213)
AU - M. D. Filipović
AU - Z. J. Smeaton
AU - B. S. Koribalski
AU - R. Kothes
AU - A. Ahmad
AU - R. Z. E. Alsaberi
AU - C. Bordiu
AU - A. C. Bradley
AU - E. J. Crawford
AU - A. M. Hopkins
AU - E. Järvelä
AU - S. Lazarević
AU - D. Leahy
AU - J. L. Payne
AU - S. F. ur Rahman
AU - G. P. Rowell
AU - H. Sano
AU - M. Selby
AU - S. S. Shabala
AU - E. J. Stanton
AU - S. Taziaux
AU - K. Tsuge
AU - D. Urosević
AU - N. F. H. Tothill
AU - J. Th. van Loon
AU - V. Velović
AU - G. L. White
PY - 2026
DA - 2026/10/15
PB - arXiv
DO - 10.48550/arxiv.2610.18285
UR - https://arxiv.org/abs/2610.18285
AB - 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 intriguing, 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 supermassive binary black hole (SMBBH) undergoing a tidal disruption event (TDE), potentially causing the peculiar radio-continuum emission.
ER -