Speaker
Description
The SC2RG survey aims to constrain the star formation history (SFH) of collisional ring galaxies (CRGs) by investigating bound stellar clusters and large-scale star-forming clumps in their field. CRGs are the result of a drop-through collision between the rotation axis of larger spiral disk galaxy and a nearby small companion. They represent a special class of interacting galaxies characterised by a ring-like structure hosting new episodes of SF which last at least 100 Myr. The starburst activities are so intense that they favour the birth of large-scale clumps, usually complexes of gravitationally bound stellar clusters with a typical age below 100 Myr and stellar masses exceeding ≈ 104 M⊙. Kpc-sized clumps represent the largest units of SF in a galaxy which make them natural laboratories for fine-tuning their host galaxy's SFH, in particular the formation process of the expanding ring-like structure in the case of CRGs. To achieve our goal, we study the physical properties of our sources of interest using photometric and spectroscopic observations of a nearby sample of CRGs. First results of the SC2RG survey reveal that the majority of the star clusters are younger than 10 Myr (i.e. in their infancy stage) with their spatial distribution across the ring likely influenced by the head-on collision between the two galaxies. We also found no evidence for any prominent cluster age sequence across the ring of one of the SC2RG targets (Arp 147). Such trend suggests that a self-propagating SF might be the main trigger for the formation of bright clumps and clusters across the ring of the CRG. We note that our work is also relevant in a way that there are only a handful cluster and clump studies hosted by CRGs to date.
| Stream | Science |
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