Giant double-double radio galaxies from LoTSS DR2

Our analysis also reveals highly misaligned DDRGs, which could be due to environmental factors and/or changes in the supermassive black hole jet ejection axes. By studying the misalignment angles, we assess the stability of the jets in these systems in relation to their environment. For the first time, we systematically characterised the large-scale environments of DDRGs, identifying their association with dense galaxy clusters and revealing the influence of "cluster weather" on their morphologies.

We have discovered a DDRG in a distant galaxy cluster at z~1.4. Our findings empirically confirm that dynamic cluster environments can induce significant misalignment in DDRGs, which aligns with previous simulation predictions and offers insights into how cluster weather shapes their morphology. Additionally, we have identified two gigahertz peaked-spectrum (GPS) candidates in the unresolved cores of the DDRGs, as well as one triple-double candidate, which, if confirmed, would be only the fifth known case.

Overall, this study enhances our understanding of the life cycle of radio AGNs and underscores the critical role of the environment in shaping the properties and evolution of giant DDRGs.