Andromeda XVII: A New Low Luminosity Satellite of M31

TL;DR

This paper reports the discovery of Andromeda XVII, a new low luminosity dwarf spheroidal galaxy near M31, providing insights into its properties, potential globular cluster associations, and implications for the satellite system of M31.

Contribution

It presents the first identification and characterization of Andromeda XVII, a faint satellite galaxy, including its distance, metallicity, luminosity, and possible globular cluster associations.

Findings

Andromeda XVII is located at ~44 kpc from M31.

It has an absolute magnitude of M_v~ -8.5.

Potential association with three globular clusters.

Abstract

We report the discovery of a new dwarf spheroidal galaxy near M31 based on INT/WFC imaging. The system, Andromeda XVII (And XVII), is located at a projected radius of ~44 kpc from M31 and has a line-of-sight distance of 794+/-40 kpc measured using the tip of the red giant branch, and therefore lies well within the halo of M31. The colour of the red giant branch implies a metallicity of [Fe/H]~-1.9 and we find an absolute magnitude of M_v~ -8.5. Three globular clusters lie near the main body of And XVII, suggesting a possible association; if any of these are confirmed, it would make And XVII exceptionally unusual amongst the faint dSph population. The projected position on the sky of And XVII strengthens an intriguing alignment apparent in the satellite system of M31, although with a caveat about biases stemming from the current area surveyed to significant depth.