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Paper: |
Gemini Spectroscopic Survey of Young Star Clusters in Merging/Interacting Galaxies |
Volume: |
423, Galaxy Wars: Star Formation and Stellar Populations in Interacting Galaxies |
Page: |
142 |
Authors: |
Trancho, G.; Bastian, N. |
Abstract: |
We present optical spectroscopy of star clusters in the merging galaxies NGC 4038/9, NGC 3256 and Stephan’s Quintet and supplement this dataset with U, B, V, I, Hα HST imaging. We derive the age and metallicity of each cluster through a comparison between observed Balmer and metal line strengths with simple stellar population models. We then estimate extinctions and masses using the photometry. We find clusters with ages between 3–600 Myr, consistent with the expected increase in the star-formation rate due to each merger. Most of the younger clusters appear to take part in the general rotation of the galaxy, hence star/cluster formation is still taking place within the galactic disks. However, two clusters in NGC 4038 and five in NGC 3256 have radial velocities consistent with being part of the halo, which is surprising given their young (60–500 Myr) ages. |
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