<p>We derive structural parameters for ~2000 globular clusters in the giant Virgo elliptical M87 using extremely deep Hubble Space Telescope images in F606W (V) and F814W (I) taken with the ACS/WFC. The cluster scale sizes (half-light radii r<sub>h</sub>) and ellipticities are determined from PSF-convolved King-model profile fitting. We find that the r<sub>h</sub> distribution closely resembles the inner Milky Way clusters, peaking at r<sub>h</sub> ≃ 2.5 pc and with virtually no clusters more compact than r<sub>h</sub> ≃ 1 pc. The metal-poor clusters average 24% larger in r<sub>h</sub> than the metal-rich ones. The cluster scale size shows a gradual and noticeable increase with galactocentric distance. Clusters are very slightly larger in the bluer waveband V, a possible hint that we may be beginning to see the effects of mass segregation within the clusters. We derive a color magnitude diagram for the M87 globular cluster system which show a clear bimodal distribution. We analyzed in the detail the sub-structure of the CMD by applying statistical fits to the color distribution. We obtain a Globular Cluster Luminosity Function for all M87 clusters and for its red and blue subpopulations. The best statistical fits describing the Luminosity Functions were also calculated. The metal-poor subpopulation has a brighter peak (mean) than the metal-rich subpopulation.</p> / Master of Science (MS)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/9328 |
| Date | 07 1900 |
| Creators | Gamboa, Madrid Juan |
| Contributors | Harris, William E., Physics and Astronomy |
| Source Sets | McMaster University |
| Detected Language | English |
| Type | thesis |
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