J023721.13-010528.5: A Giant S -shaped Radio Galaxy Showing Four Episodes of Jet Activity
- 1Indian Institute of Science Education and Research
- 2National Centre for Radio Astrophysics - Tata Institute of Fundamental Research
Abstract
We present high-sensitivity, high-resolution radio observations of J023721.13−010528.5 using the upgraded Giant Metrewave Radio Telescope in band-3 (250–500 MHz) and band-4 (550–950 MHz), along with MeerKAT (1280 MHz) and VLA (3 GHz) survey images. The radio source, hosted by a bright cluster galaxy at redshift z = 0.372, is a giant radio galaxy with a projected linear size between the outermost hotspots of 1.2 Mpc and is one of the largest S -shaped radio sources known. Its radio morphology revealed four pairs of components straddling the radio core, which were also local maxima in profiles of radio flux densities and equipartition energy density measured along the radio lobes. Spatially resolved multifrequency spectral analysis showed progressively older emission from the inner to the outer components, spanning approximately 4–21 Myr. The high degree of symmetry of the inner three component-pairs with respect to the radio core makes it improbable that these are randomly located knots in the radio jet. Therefore, we present J023721.13−010528.5 as the prototype of a new class of radio galaxies with four episodes of jet activity—a quadruple-double radio galaxy. We suggest that giant S -shaped radio sources may be among the most promising targets for identifying and studying multiepoch radio jet activity, since their large linear sizes and jet-axis evolution can spatially separate hotspots from successive episodes, making them easier to detect and analyze.
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BibTeX
@article{khadekar2026j023721130105285,
title = {{J023721.13-010528.5: A Giant S -shaped Radio Galaxy Showing Four Episodes of Jet Activity}},
author = {Pavan Vijay Khadekar and Dharam Vir Lal and Ramana Athreya},
journal = {The Astrophysical Journal},
year = {2026},
month = oct,
doi = {10.3847/1538-4357/aea20c},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/aea20c},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - J023721.13-010528.5: A Giant S -shaped Radio Galaxy Showing Four Episodes of Jet Activity
AU - Pavan Vijay Khadekar
AU - Dharam Vir Lal
AU - Ramana Athreya
PY - 2026
DA - 2026/10/21
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/aea20c
UR - https://iopscience.iop.org/article/10.3847/1538-4357/aea20c
AB - We present high-sensitivity, high-resolution radio observations of J023721.13−010528.5 using the upgraded Giant Metrewave Radio Telescope in band-3 (250–500 MHz) and band-4 (550–950 MHz), along with MeerKAT (1280 MHz) and VLA (3 GHz) survey images. The radio source, hosted by a bright cluster galaxy at redshift z = 0.372, is a giant radio galaxy with a projected linear size between the outermost hotspots of 1.2 Mpc and is one of the largest S -shaped radio sources known. Its radio morphology revealed four pairs of components straddling the radio core, which were also local maxima in profiles of radio flux densities and equipartition energy density measured along the radio lobes. Spatially resolved multifrequency spectral analysis showed progressively older emission from the inner to the outer components, spanning approximately 4–21 Myr. The high degree of symmetry of the inner three component-pairs with respect to the radio core makes it improbable that these are randomly located knots in the radio jet. Therefore, we present J023721.13−010528.5 as the prototype of a new class of radio galaxies with four episodes of jet activity—a quadruple-double radio galaxy. We suggest that giant S -shaped radio sources may be among the most promising targets for identifying and studying multiepoch radio jet activity, since their large linear sizes and jet-axis evolution can spatially separate hotspots from successive episodes, making them easier to detect and analyze.
SN - 0004-637X
SN - 1538-4357
ER -