Abstract Details
| Name: Suvajit Sardar Affiliation: Indian Institute of Space Science and Technology Conference ID: ASI2025_512 Title : Decoding the morphology and kinematics of the neutral gas in the Sacred Mushroom collisional ring galaxy system Authors and Co-Authors : Suvajit Sardar 1, Sriram Sankar 2, Anand Narayanan 1 Abstract Type : Poster Abstract Category : Galaxies and Cosmology Abstract : Collisional Ring Galaxies (CRGs) are a rare class of galaxies that form when an intruder galaxy passes through the disk of the target galaxy, creating a characteristic ring-like structure. They are thus a result of galactic-scale drop-through perturbation experiments. The 21cm neutral hydrogen line (HI) is a powerful tracer that can probe the gas kinematics of the neutral phase spanning the interstellar medium (ISM), inner circumgalactic medium (CGM) and the intra-group medium (IGrM). The relatively simple interaction configurations of CRGs allow us to investigate how galactic interactions impact star formation, gas kinematics, morphology, and the larger baryon cycle shaping galaxy evolution. Yet, the study of HI in CRGs remains limited, leaving key questions about the large-scale changes that happen to their gas-star formation cycles unanswered. The MeerRings program using the SKA-mid-precursor, MeerKAT radio telescope, will perform the first census of the HI in a substantial sample of CRGs in the local universe. In this work, we present results from the HI study of the Sacred Mushroom CRG, which hosts a stellar disc that spans 40 kpc across the major axis. MeerKAT’s unparalleled sensitivity and resolution enable us to map, for the first time, the distribution and kinematics of HI down to ∼ 3 × 10^(19) cm^(−2) at ∼ 5.4 kpc spatial and ∼ 5.5 km/s spectral resolutions. Based on our resolved analysis of the gas morphology and kinematics, we present our hypothesis on how the galaxy interaction has led to the exchange of gas between the target galaxy and the intruder, and the subsequent ring formation resulting from the density waves triggered by the perturbation. |