2010/01/29 by Anne Pellerin, Gerhardt R. Meurer, Kenji Bekki +3
Physics and Astronomy · #Astronomy and Astrophysical Research #Cluster (spacecraft) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Population #Ring (chemistry) #Star cluster #Star formation #Stellar population #Stellar, planetary, and galactic studies #astro-ph.CO
paper · pdf · doi:10.1088/0004-6256/139/4/1369
17 pages including 13 figures. Accepted for publication in AJ. Full resolution version at http://people.physics.tamu.edu/pellerin/Pellerin_etal_NGC922.pdf
arxiv created 2010/01/29 · openalex publication_date 2010/02/25 · arxiv updated 2015/05/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present a detailed study of the star cluster population detected in the galaxy NGC 922, one of the closest collisional ring galaxies known to date, using Hubble Space Telescope /Wide Field Planetary Camera 2 UBVI photometry, population synthesis models, and N -body/smoothed particle hydrodynamics simulations. We find that 69% of the 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 cluster luminosity function slope of 2.1–2.3 for NGC 922 is in agreement with those of young clusters in nearby galaxies. Models of the cluster age distribution match the observations best when cluster disruption is considered. We also find clusters with ages (>50 Myr) and masses (>10 5 M ☉ ) that are excellent progenitors for faint fuzzy clusters. The images also show a tidal plume pointing toward the companion. Its stellar age from our analysis is consistent with pre-existing stars that 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.