New Delhi: Researchers from the Indian Institute of Astrophysics have used 3D hydrodynamical simulations to investigate and reproduce the complex morphology
of a recently discovered Twin Radio Galaxy (TRG). These exotic objects are formed during mergers between a pair of massive galaxies, each hosting a supermassive black hole (SMBH) in their cores that emit bipolar jets. Only three such TRGs have been discovered so far, with the latest, discovered in 2022 being designated as TRG J104454+354055. The galaxy itself was detected by the upgraded Giant Metrewave Radio Telescope (uGMRT) located near Pune, with the previous two TRGs discovered over three decades ago.
Both the sets of radio jets on the newly discovered TRDG can be resolved at distances of 0.3 million lightyears, along with clearly visible helical and bending structures. The pair of SMBHs are separated by a distance of about 0.1 million lightyears. The complex morphology of the TRG was simulated, with researchers discovering that the bipolar jets remain well-separated and propagate in parallel without interacting with each other. The simulations matched the observations. The researchers were able to track the swiveling or precession of the twin plasma jets, and how they formed the observed structures. A paper describing the research has been published in The Astrophysical Journal.
Evolution of the galaxy merger
Lead author of the paper, Santanu Mondal explains, “The newly discovered TRG offered a rare opportunity as a unique testbed to try and understand such complex systems. Despite their clean morphology, we hardly know about the physical reason behind their observed appearance and underlying origin.” Ravi Joshi, part of the original discovery team said, “We found that our 3D simulations were able to explain the observed morphology satisfactorily for a set of parameters. The simulations were also able to tell us how this morphology evolved over the last 190 million years due to the gravitational interaction between the two galaxies.”
