Name: Sushant Dutta
Affiliation: Physical Research Laboratory, Ahmedabad
Conference ID : ASI2022_41
Title : Remnant Radio Galaxies Detected in Deep Low-frequency Radio Surveys
Authors : Sushant Dutta (PRL, Ahmedabad), Veeresh Singh (PRL, Ahmedabad), Yogesh Wadadekar (NCRA-TIFR) and C. H. Ishwara-Chandra (NCRA-TIFR)
Abstract Type: Oral
Abstract Category : Extragalactic Astronomy
Abstract : The cessation of active galactic nuclei (AGN) activity can be well detected in radio galaxies characterized by absent core, amorphous lobes of low-surface brightness and strong spectral curvature. Remnant radio galaxies are believed to be rare objects that can be observed over a relatively short time window before the radio lobes, with no supply of fresh plasma, completely fade away due to radiative and dynamical energy losses. In our recent work, we searched and characterized the population of remnant radio galaxies using sensitive 150 MHz LOFAR, 325 MHz GMRT, and 1.4 GHz JVLA radio observations. In our study, we obtained one of the largest samples of remnants reaching down to the fainter regime (10 mJy at 150 MHz). For the first time, our study demonstrated the existence of a substantial population of small-size (< 200 kpc) remnants suggesting that the less abundant large-size remnants are likely to have a shorter remnant phase. In this presentation, I would also emphasize on the potential of SKA-pathfinder telescopes to discover remnant radio galaxies over an unexplored regime of flux density and redshift.