uGMRT Sub-GHz View of the Sausage Cluster Diffuse Radio Sources

Abstract CIZA J2242.8+5301, or the Sausage cluster, is well-studied over a range of frequencies. Since its first discovery, a lot of interesting features and unique characteristics have been uncovered. In this work, we report some more new morphological features using the uGMRT band-3 and band-4 data. In the north relic, we observe variation in the spectral index profiles across the relic width from the east to west, which may indicate a decrease in the downstream cooling rate in that direction. We reconfirm the presence of an additional ∼930 kpc relic in the north. We classify the filamentary source in the downstream region to be a narrow-angle tail (NAT) radio galaxy. The bright arc in the east relic shows a substructure in the spectral index profile, which may indicate the presence of finer filaments. We further report the presence of a double-strand structure in the east relic similar to the “Toothbrush” relic. We categorize the bright “L”-shaped structure in the southern relic to be a NAT radio galaxy, as well as trace the actual ∼1.1 Mpc relic component. We reconfirm the existence of the faint southern extent, measuring the relic length to be ∼1.8 Mpc. Furthermore, we suggest the southern relic to be a union of individual component relics rather than a single giant filamentary relic. Lastly, based on the morphological symmetry between northern and southern relics, we suggest a schematic shock structure associated with the merger event in an attempt to explain their formation scenario.