| Name: | Apoorva Prakash |
| Affiliation: | Jain University (Deemed-to-be) |
| Conference ID : | ASI2024_513 |
| Title : | Understanding radio bubbles in galaxies with/without AGN jets |
| Authors : | Apoorva Prakash1,2, Prasun Machado2, Pratik Dabhade2,4, Kiran Kumar 1, Arundhati Purohit 2, Ananda Hota2,4
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| Authors Affiliation: | 1) Jain University, Bangalore
2) RAD@home Astronomy Collaboratory, India
3) Instituto de Astrof´ısica de Canarias, Tenerife, Spain
4) UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai
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| Mode of Presentation: | Poster |
| Abstract Category : | Galaxies and Cosmology |
| Abstract : | Almost all powerful radio galaxies are hosted in elliptical galaxies. They are accepted as the major kinematic-drivers for the merger and AGN feedback-driven galaxy evolution. Only a dozen rare cases like “Speca” are spiral/disk galaxies and host standard 300 kpc to Mpc size radio sources. Speca -like galaxies have somehow avoided mergers but have similar powerful lobe feedbacks. On the other hand, low-power, kpc-size radio bubbles are known in nearby spiral galaxies. They have often been ignored in the context of AGN feedback. In a sample of 10 radio bubble galaxies, all of them are known to have spectral line signatures of Seyferts, evidence of bubble-AGN connection. The Milky Way Galaxy is the only known case of a radio bubble (Fermi bubble) with no optical signature of AGN activity. Only with the Event Horizon Telescope image of Sgr A* we know that the accretion onto the blackhole is probably active. Since 10 of these bubbles were from VLA imaging studies, we looked for signs of older-extended or episodic nature in the LoTSS images from LOFAR. Given the limited sky coverage, only four of the sample radio bubbles are imaged by LOFAR. Although disk emissions were prominent, we did not find any new bubble-like features except in the minor companion of M51. We suggest that such low-power jets take the shape of bubbles due to the interaction with the rotating ISM and/or magneto-ionic bubbles/cavities pre-existing in the halo of the galaxy by the starburst-driven superwinds. Since 5 out of 10 galaxies have bars and two of the rest are disturbed due to interaction/merger, the dynamical-trigger process is long-lasting (billion years) and hence it is unlikely that these short-term (a few million year) jet/bubble feedbacks in galaxies do not occur in multiple episodes.
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