The stellar content of the Sagittarius Dwarf Galaxy

TL;DR

This study provides deep photometric analysis of the Sagittarius Dwarf Galaxy, revealing a metallicity spread and a dominant old stellar population similar to associated globular clusters, with an estimated distance of 24.55 Kpc.

Contribution

It offers detailed photometric data and analysis of Sgr's stellar populations, highlighting their metallicity diversity and similarity to globular clusters like Terzan 7.

Findings

Sgr has a metallicity spread among its stars.

The dominant population is about 10 Gyr old.

Distance to Sgr is approximately 24.55 Kpc.

Abstract

We present V,I deep CCD photometry for three fields of the dwarf galaxy in Sagittarius (Sgr). One of the fields is centered on the globular cluster NGC 6715 (M54), which lies in one of the dense clumps of the Sgr galaxy. Comparing the CMD of Sgr with those of globular clusters which are believed to be kinematically associated with the dwarf galaxy, we conclude that the stellar population of Sgr presents a spread in metallicity, and that the dominant population (about 10 Gyr old) is extremely similar to the star content of the associated globular cluster Terzan 7. The estimated distance to Sgr is about d=24.55 Kpc.