Evolutionary link between ultra-diffuse galaxies and dwarf early-type galaxies

TL;DR

This study uses spectroscopic data from a new instrument to analyze low-luminosity galaxies, revealing that internal and environmental processes link ultra-diffuse galaxies with dwarf early-type galaxies.

Contribution

It introduces a comprehensive observational and analytical approach to study the evolution of faint galaxies, establishing an evolutionary connection between UDGs, dSph, and dE galaxies.

Findings

UDGs show properties consistent with both internal feedback and environmental effects.

The data supports an evolutionary link between UDGs, dwarf spheroidals, and dwarf ellipticals.

Internal and external processes jointly shape the properties of low-luminosity galaxies.

Abstract

Spectroscopic studies of low-luminosity early-type galaxies are essential to understand their origin and evolution but remain challenging because of low surface brightness levels. We describe an observational campaign with the new high-throughput Binospec spectrograph at the 6.5-m MMT. It targets a representative sample of dwarf elliptical (dE), ultra-diffuse (UDG), and dwarf spheroidal (dSph) galaxies. We outline our data analysis approach that features (i) a full spectrophotometric fitting to derive internal kinematics and star formation histories of galaxies; (ii) two-dimensional light profile decomposition; (iii) Jeans anisotropic modelling to assess their internal dynamics and dark matter content. We present first results for 9 UDGs in the Coma cluster and a nearby dSph galaxy, which suggest that a combination of internal (supernovae feedback) and environmental (ram-pressure stripping, interactions) processes can explain observed properties of UDGs and, therefore, establish an evolutionary link between UDGs, dSph, and dE galaxies.