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Antlia: an outskirt Local Group Galaxy

Marco Castellani·Giuseppe Bono·Santi Cassisi·Gianni Marconi·Anna Piersimoni
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Abstract

Deep (I,V-I) and (I,B-I) color-magnitude diagrams (CMDs) of the Antlia dwarf galaxy, based on Science Verification (SV) data collected with the FORS I camera on the ESO Very Large Telescope (VLT) are presented. By adopting the new calibration of the Tip of the Red Giant Branch (TRGB) provided by Salaris & Cassisi (1998) we estimated that the Antlia distance modulus is (m-M)o=25.98 with an error of 0.10 mag. We suggest an improvement of the classical TRGB method based on infrared H and K magnitudes of TRGB stars. Such a method should overcome the well-known limit of the "classical" TRGB method when dealing with metal-rich stellar populations.

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Marco Castellani, Giuseppe Bono, Santi Cassisi, Gianni Marconi, Anna Piersimoni. 2000-08-04. Antlia: an outskirt Local Group Galaxy. https://arxiv.org/abs/astro-ph/0008080

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