# Nuclei of dwarf spheroidal galaxies KKs3 and ESO269-66 and their counterparts in our Galaxy

## TL;DR

This study analyzes the chemical compositions, ages, and structures of globular clusters in two dwarf spheroidal galaxies and compares them with Galactic GCs, revealing similar formation conditions despite different environments.

## Contribution

It provides the first detailed chemical and structural analysis of GCs in the isolated dSph KKs3 and the galaxy ESO269-66, highlighting their similarities with Galactic GCs.

## Key findings

- GCs in both dSphs have similar ages (~12.6 Gyr) and chemical compositions.
- Galactic GCs show extended blue horizontal branches and multiple populations.
- Formation conditions of these GCs were similar around 1 Gyr after the Big Bang.

## Abstract

We present the analysis of medium-resolution spectra obtained at the Southern African Large Telescope (SALT) for nuclear globular clusters (GCs) in two dwarf spheroidal galaxies (dSphs). The galaxies have similar star formation histories, but they are situated in completely different environments. ESO269-66 is a close neighbour of the giant S0 NGC5128. KKs3 is one of the few truly isolated dSphs within 10 Mpc. We estimate the helium abundance $Y=0.3$, $\rm age=12.6\pm1$ Gyr, $[Fe/H]=-1.5,-1.55\pm0.2$ dex, and abundances of C, N, Mg, Ca, Ti, and Cr for the nuclei of ESO269-66 and KKs3. Our surface photometry results using HST images yield the half-light radius of the cluster in KKs3, $\rm r_h=4.8\pm0.2$ pc. We demonstrate the similarities of medium-resolution spectra, ages, chemical compositions, and structure for GCs in ESO269-66 and KKs3 and for several massive Galactic GCs with $[Fe/H]\sim-1.6$ dex. All Galactic GCs posses Extended Blue Horizontal Branches and multiple stellar populations. Five of the selected Galactic objects are iron-complex GCs. Our results indicate that the sample GCs observed now in different environments had similar conditions of their formation $\sim$1 Gyr after the Big Bang.