2003/05/12 by R. de Grijs, Richard de Grijs, P. Anders +7
Medicine · Physics and Astronomy · #Abell 2744 #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Cluster (spacecraft) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy groups and clusters #Initial mass function #Medicine #Metallicity #Physics #Population #Ring (chemistry) #Star cluster #Star formation #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2003.06777.x
published as Mon.Not.Roy.Astron.Soc.343:1285,2003 · 17 pages LaTeX, incl. 11 postscript figures, accepted for publication in MNRAS
arxiv created 2003/05/12 · openalex publication_date 2003/08/21 · arxiv updated 2012/08/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We use the ages, masses and metallicities of the rich young star cluster systems in the nearby starburst galaxies NGC 3310 and 6745 to derive their cluster formation histories and subsequent evolution. We further expand our analysis of the systematic uncertainties involved in the use of broad-band observations to derive these parameters (Paper I) by examining the effects of a priori assumptions on the individual cluster metallicities. The age (and metallicity) distributions of both the clusters in the circumnuclear ring in NGC 3310 and of those outside the ring are statistically indistinguishable, but there is a clear and significant excess of higher-mass clusters in the ring compared to the non-ring cluster sample. It is likely that the physical conditions in the starburst ring may be conducive for the formation of higher-mass star clusters, on average, than in the relatively more quiescent environment of the main galactic disc. For the NGC 6745 cluster system we derive a median age of ∼10 Myr. NGC 6745 contains a significant population of high-mass ‘super star clusters’, with masses in the range 6.5 ≲ log(Mcl/M⊙) ≲ 8.0. This detection supports the scenario that such objects form preferentially in the extreme environments of interacting galaxies. The age of the cluster populations in both NGC 3310 and 6745 is significantly lower than their respective characteristic cluster disruption time-scales, respectively log(tdis4/yr) = 8.05 and 7.75, for 104 M⊙ clusters. This allows us to obtain an independent estimate of the initial cluster mass function slope, α= 2.04(±0.23)+0.13−0.43 for NGC 3310, and 1.96(±0.15) ± 0.19 for NGC 6745, respectively, for masses Mcl≳ 105 M⊙ and Mcl≳ 4 × 105 M⊙. These mass function slopes are consistent with those of other young star cluster systems in interacting and starburst galaxies.