List of spiral DRAGNs
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Spiral DRAGNs or Speca-like galaxies are a type of spiral galaxies which are also radio galaxies or which contain DRAGNs (Double Radio-source Associated with Galactic Nucleus).
Most DRAGNs are associated with elliptical galaxies, as are most double-lobed radio-galaxies.[1] Spiral DRAGNs are inconsistent with currently known galaxy formation processes.[2] As of 2023, there are nearly 36 spiral DRAGNs.[3]
Lenticlular galaxies containing DRAGNs are as rare as spiral DRAGNs, with only 5 known examples as of 2020,[4] including: Centaurus A,[5][6] NGC 612[7] and NGC 1534.[4] Nearby Seyfert galaxies containing small or galaxy-scale radio jets/lobes are not accepted as Specas or Spiral DRANGs.
The first spiral-host large radio galaxy, 0313-192, was discovered in 1998 by Michael J. Ledlow, Frazer N. Owen, and William C. Keel.[8] After more than a decade the second case, Speca, was discovered by Ananda Hota and his collaborators in 2011.[9] Since Speca was also episodic, two pairs of radio lobes on either sides of the host, it removed all doubts on possible background galaxy confusing as the host. Hereafter the search for Speca-like galaxy got intensified and by 2023 the total number of such galaxies has increased to three dozens, establishing itself as a new class of radio galaxies.[3]
List
| Galaxy | Identified Date | Notes | References |
|---|---|---|---|
| ESO 0313-192 | 1998 | First known spiral DRAGN, located in Abell 428. It is the first spiral DRAGN with VLBI detection.[10] | [11][12][8] |
| ESO 248-G10 | 2000 | Second known spiral DRAGN, one of the largest with a scale of 2.51 megaparsecs. | [13] |
| Speca | 2011 | First confirmed case due to its episodic radio jet nature. Hosted in a massive spiral and with giant Mpc-scale radio-lobes. It was the second galaxy shown to have three episodes of periodic activity, the first was an elliptical.[NB 1] | [9][14][12] |
| J2345-0449 | 2014 | Third known spiral DRAGN with two episodic activities, observed at radio wavelengths and measuring about 1.6 megaparsecs in total size. | [15] |
| SDSS J1649+2635 | 2014 | Fourth known spiral DRAGN; first located in a grand design spiral galaxy. It was discovered by cross-matching spiral galaxies identified by galaxy zoo volunteers with the Unified Radio Catalog. It was the first systematic search for spiral DRAGNs. | [1][16][12][17] |
| J0836+0532 | 2015 | Two clear spiral arms | [18] |
| J1159+5820 | 2012/2015 | Candidate: Disturbed galaxy with signs of a merger. | [19][18] |
| J1352+3126 | 2015 | Candidate: Galaxy was well studied at the time of the discovery by Singh et al. The galaxy was classified as spiral or irregular galaxy. | [18] |
| MCG+07-47-10 | 2016 | radio source has a low luminosity | [20] |
| NGC 6185 | 2022 | The largest known spiral DRAGN, the scale of the radio lobes is 2.54 Mpc. | [21][22] |
| J0354-1340 | 2022 | spiral host that is a narrow-line Seyfert 1, size of the de-projected jets is 250 kpc | [23] |
| J0209+0750 | 2022 | loose spiral arms, has star-forming clumps | [24] |
| J0806+0624 | 2022 | several spiral arms and a luminous bar-like feature | [24] |
| J1328+5710 | 2022 | low-mass, low-redshift galaxy with many star-forming regions, at least two prominent arms and a strong bar. One of the few intermediate massive black holes (≤ 105 M☉) with a strong radio emission and the first with a double-lobed radio emission. | [24] |
| J1656+6407 | 2022 | extremely massive star-forming spiral galaxy | [24] |
| J1128+2417 | 2022 | star-forming clumps in the arms | [24] |
| J1646+383 | 2022 | dust-lane with peculiar arc-like shape | [24] |
| J0326-0623 | 2023 | two major spiral arms, scale of the radio lobes is 430 kpc | [3] |
| J1110+0321 | 2023 | scale of the radio lobes is 100 kpc | [3] |
| J1134+3046 | 2023 | scale of the radio lobes is 380 kpc | [3] |
| NGC 5383 | 2023 | Second spiral DRAGN found to be hosted by a grand design spiral galaxy, scale of the radio lobes is 70 kpc. | [25] |
| LEDA 896325 | 2025 | Similar to Speca and J2345-0449 this is episodic and giant (2Mpc) | [26] |
Notes
- SPECA = Spiral-host Episodic radio galaxy tracing Cluster Accretion