Speaker
Description
Collisional Ring Galaxies (CRGs) form when a small galaxy companion passes through the larger disk galaxy in its central region, creating a radial density wave that compresses the gas and triggers intense star formation (SF) across a bright structured ring. Although rare, these systems provide a suitable environment to study interaction-induced SF processes and to constrain galactic evolution models. In particular, the blue stellar clumps, also known as young massive star cluster complexes, with typical ages below ~100 Myr are interesting because they represent recent episodes of massive SF. We report the sample overview of an ongoing survey dubbed the Stellar Clusters in Collisional Ring Galaxies (SC2RG). SC2RG is a systematic study of a representative sample of nearby CRGs to investigate SF mechanisms in these intriguing galaxies. Using multi-band HST images, this work specifically investigates stellar clusters and large-scale clumps of the CRGs to help reconstruct their star formation history. We also present preliminary results from a comprehensive clump analysis of Arp 261, which is one of the nearest SC2RG targets located at a distance of 30 Mpc. We identified 18 blue clumps with blue B-I colours (typical of a young stellar population) across the galaxy. Yggdrasil SSP models overplotted on the colour magnitude diagram of the clumps suggest that these clumps can be as massive as 106M☉. The stellar clump study of Arp 261 is meant to establish the baseline of the full SC2RG sample. The upcoming steps will focus on refining physical parameter estimates and investigating how the spatial distribution of blue clumps relates to the dynamical evolution driven by the head-on collision.
| Stream | Science or Engineering |
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