Daily Image
12-12-2023
LOFAR Uncovers a twisted AGN radio remnant in Abell 1318
| Submitter: | Aleksandar Shulevski |
| Description: | In one of the LoTSS DR2 mosaics, this beautiful very low surface brightness emission region was detected which prompted an extended observing campaign to ascertain its properties. We observed it with uGMRT and also used APERTIF images to derive its spectral index. It turned out that there is a distribution of spectral indices across the source, indicating an interesting ageing (hi)story of up to 250 Myr. We have used Swift X-ray data to look into the thermal emission of the inter-galactic medium and determined that Abell 1318 in which this source is embedded is still dynamically active; the remnant filamentary morphology may be sculpted by gas sloshing induced by movement of group members. The image highlights various points of interest: the large dashed white circle is the R200 radius of the galaxy group whose brightest member we propose is the AGN host galaxy (marked with a larger white circle). Some of the identified group galaxy members are marked with small yellow circles. Their dynamics helped us to determine the group mass and infer that it is indeed a galaxy group as opposed to a cluster. The green circle marks the region around the target in which we identified LoTSS catalog radio sources (white squares). The yellow cross and magenta triangle markers show the positions of X-ray extended and point source emission we were able to detect. The AGN remnant is offset from the proposed host galaxy, and there seems to be multiple episodes of activity indicated by the LOFAR radio emission (red). Further studies would definitely be of interest to determine the interplay between the environment and history of the AGN activity in this system. The article showcasing the image is accepted for publication in A&A. |
| Copyright: | CC-BY-SA 4.0 (Credit: Aleksandar Shulevski) |
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