| Name: | Sushant Dutta |
| Affiliation: | Physical Research Laboratory, Ahmedabad |
| Conference ID : | ASI2023_195 |
| Title : | Remnant Radio Galaxies : Characteristics, Environments and Ages |
| Authors : | Author: Sushant Dutta (PRL, Ahmedabad)
Co-Authors: Veeresh Singh (PRL, Ahmedabad), C. H. Ishwara-Chandra (NCRA-TIFR, Pune), Yogesh Wadadekar (NCRA-TIFR, Pune) and Abhijit Kayal (PRL, Ahmedabad) |
| Mode of Presentation: | Oral |
| Abstract Category : | Extragalactic Astronomy |
| Abstract : | The cessation of active galactic nuclei (AGN) activity in radio galaxies leads them into remnant phase. Remnant radio galaxies are believed to be rare objects as they can be observed over a relatively short period of time before the radio lobes with no supply of fresh plasma completely fade away due to radiative and dynamical energy losses. The timescales of remnant phase and AGN duty cycle are vital to understanding the evolution of radio galaxies. In our recent work, we
identified and characterized remnants using one of the deepest multi-frequency radio observations performed at 150 MHz, 325 MHz and 1.4 GHz using LOFAR, GMRT and JVLA, in the XMM-LSS field. In our study, we exploited faint (10 mJy at 150 MHz) and high redshift (z ~ 1.0) regime and unveiled the largest remnant sample till date. Also, for the first time, we demonstrated the existence of a substantial population of small-size (< 200 kpc) remnants. Contrary to the previously perceived notion, we find that the majority of remnants reside in a less dense environment and can have relatively short ages due to the combined effects of dominant inverse Compton losses at high redshift and the plausible rapid expansion of lobes. In this presentation, I shall also touch upon the need for deep large-area multi-frequency radio surveys to understand the diversity and evolution of remnants. |
