Back to Volume
Paper: The Collisional Ring Galaxy NGC 922
Volume: 423, Galaxy Wars: Star Formation and Stellar Populations in Interacting Galaxies
Page: 19
Authors: Pellerin, A.; Meurer, G. R.; Bekki, K.; Elmegreen, D. M.; Wong, O. I.; Knezek, P. M.
Abstract: We present a detailed study of the star cluster population detected in the galaxy NGC 922, one of the closest collisional ring galaxies, using HST/WFPC2 UBVI photometry, population synthesis models, and N-body/SPH simulations. We find that most clusters are younger than 7 Myr, and that most of them are located in the ring or along the bar, consistent with the strong Hα emission. The observed age distribution displays a slope not consistent with the simulated star formation history of NGC 922. However our simulations match the cluster age distribution best when cluster disruption is considered. We also find clusters with ages ( >50 Myr ) and masses ( >105 Msun ) that are excellent progenitors for faint fuzzy clusters. The images also show a tidal plume pointing toward the companion. Its stellar age suggests that it consists of stars significantly older than the epoch of collision and that they were stripped off during the passage of the companion. Finally, a comparison of the star-forming complexes observed in NGC 922 with those of a distant ring galaxy from the GOODS field indicates very similar masses and sizes, suggesting similar origins.
Back to Volume