Feedback by radio-loud active galactic nuclei ( AGN ) in galaxy groups is not fully understood .
Open questions include the duty cycle of the AGN , the spatial extent of the radio lobes , the effect they have on the intragroup medium , and the fate of the cosmic rays .
We present the discovery of a 650 kpc-radio galaxy embedded in steep diffuse emission at z = 0.18793 \pm 5 \times 10 ^ { -5 } located at the center of the galaxy group MaxBCG J199.31832+51.72503 using an observation from the LOFAR Two-meter Sky Survey ( LoTSS ) at the central frequency of 144 MHz .
Subsequently , we performed a GMRT observation at the central frequency of 607 MHz to study the spectral properties of the source .
The observations reveal a radio galaxy with a total radio power P _ { tot, 1.4 } \sim 2.1 \times 10 ^ { 24 } W Hz ^ { -1 } , exhibiting two asymmetrical jets and lobes .
The derived spectral index map shows a steepening toward the inner regions and a steep-spectrum core region .
We model the integrated radio spectrum , providing two possible interpretations : the radio source is evolved but still active or it is just at the end of its active phase .
Finally , in the same field of view we have discovered Mpc-sized emission surrounding a close pair of AGN located at a redshift z = 0.0587 \pm 2 \times 10 ^ { -4 } ( SDSS J131544.56+521213.2 and SDSS J131543.99+521055.7 ) which could be a radio remnant source .