Globular Clusters and Dwarf Spheroidal Galaxies

TL;DR

This paper explores the use of ellipticity as a new criterion to differentiate between globular clusters and dwarf spheroidal galaxies, addressing overlaps in traditional classification parameters.

Contribution

It introduces ellipticity as an additional distinguishing feature to better classify these celestial objects.

Findings

Ellipticity can help distinguish some globular clusters from dwarf spheroidal galaxies.

Traditional criteria sometimes overlap, making classification challenging.

Ellipticity provides a new perspective for classification in ambiguous cases.

Abstract

Traditionally globular clusters and dwarf spheroidal galaxies have been distinguished by using one or more of the following criteria: (1) mass, (2) luminosity, (3) size, (4) mass-to-light ratio and (5) spread in metallicity. However, a few recently discovered objects show some overlap between the domains in parameter space that are occupied by galaxies and clusters. In the present note it is shown that ellipticity can, in some cases, be used to help distinguish between globular clusters and dwarf spheroidal galaxies.