Spectral Energy Distributions and Age Estimates of 78 Star Clusters in M33

Abstract

In this third paper of our series, we present CCD spectrophotometry of 78 star clusters that were detected by Chandar, Bianchi, & Ford in the nearby spiral galaxy M33. CCD images of M33 were obtained as a part of the BATC Color Survey of the sky in 13 intermediate-band filters from 3800 to 10000Å. By aperture photometry, we obtain the spectral energy distributions of these 78 star clusters. As Chandar, Bianchi, & Ford did, we estimate the ages of our sample clusters by comparing the photometry of each object with theoretical stellar population synthesis models for different values of metallicity. We find that the sample clusters formed continuously in M33 from $\sim 3\times 10^6$ -- $10^{10}$ years. This conclusion is consistent with Chandar, Bianchi, & Ford. The results also show that, there are two peaks in cluster formation, at $\sim 8\times 10^6$ and $\sim 10^9$ years in these clusters.

29 pages, one figure is gif form, will appear in the June 2002 issue of AJ

References in corpus (3)

• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• Spatially resolved Spectro-photometry of M81: Age, Metallicity and Reddening Maps
• SED, Metallicity and Age of Halo Globular Clusters in M33

Cited by in corpus (19)

• A Catalog of Star Cluster Candidates in M33
• The Outer Regions of the Nearby Sc Galaxies NGC 2403 and M33: Evidence for an Intermediate Age Population at Large Radii
• Spectral Energy Distributions and Age Estimates of 172 Globular Clusters in M31
• The M33 Globular Cluster System with PAndAS Data: The Last Outer Halo Cluster?
• New age estimates of M31 globular clusters from multi-colour photometry
• A "super" star cluster grown old: the most massive star cluster in the Local Group
• Star clusters in M33: updated UBVRI photometry, ages, metallicities, and masses
• Newly Identified Star Clusters in M33. II. Radial HST/ACS Fields
• Newly Identified Star Clusters in M33. I. Integrated Photometry and Color-Magnitude Diagrams
• SAO-6m Telescope Spectroscopic Observations of Globular Clusters in Nearby Galaxies
• Metallicity Estimates for Old Star Clusters in M33
• Young stellar clusters and associations in M33
• An updated catalog of M33 clusters and candidates: $UBVRI$ photometry, and some statistical results
• Ages of M33 Star Clusters Based on the HST/WFPC2 Photometry
• Ages and Masses of Star Clusters in M33: a Multi-wavelength Study
• New $ubvri$ photometry of 234 M33 star clusters
• Overview of charmonium decays and production from Non-Relativistic QCD
• Multiwavelength study of nearly face-on low surface brightness disk galaxies
• Multicolor photometry of 145 of the HII regions in M33