AAS 201st Meeting, January, 2003
Session 81. Extragalactic Star Clusters
Poster, Wednesday, January 8, 2003, 9:20am-6:30pm, Exhibit Hall AB

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[81.01] Globular Cluster Systems in Dwarf Galaxies

A. Seth (Univ. of Washington), K. Olsen (CTIO), B. Miller (Gemini South)

We conducted a search for globular clusters using HST snapshot data of 30 dwarf irregular and elliptical galaxies in the Virgo and Fornax clusters. We distinguished semi-resolved sources in the galaxies by creating a PSF from stellar data (using DAOPHOT II) and convolving it with King profiles with a range of core radii. A core radii for each source was determined by finding the best fitting convolved PSF. Over 1000 sources were found in the 30 galaxies, a large fraction of which belong to two higher surface brightness galaxies. Artificial star/cluster tests allow us to determine our completeness as a function of core radii and determine an uncertainty on the size measurements of the sources. For point sources, we are 50% complete above roughly V=25 corresponding to an absolute magnitude of -6. The uncertainty in core radii is roughly 1 pc. We use the neighboring 'blank' wide field chips to help determine the background and foreground contamination. The resulting magnitudes, colors, sizes and specific frequencies of these 30 globular cluster systems provide a significant dataset to help determine the nature of globular cluster systems in dwarf irregular and elliptical galaxies.

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Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.