Dwarf galaxies are the essential ingredients in the buildup of large complex galaxies. They are relatively simple systems; yet their observed properties are somewhat at odds with theoretical predictions from ΛCDM cosmological models. The influence of the environment where they form, in particular, is the decisive factor to understand their long-term evolution, but it is hard to separate from intrinsic factors such as feedback. 

A key to better understand these issues is to look at dwarfs that had little or no interactions with other galaxies. VV124, in particular, is the most isolated dwarf in the Local Group, believed to have evolved in isolation for a Hubble time. In this talk I will present an investigation of this galaxy through the study of its variable stars, revealed with our HST/ACS observations. We found pulsating stars belonging to old (RR Lyrae), intermediate (Anomalous Cepheid) and young (Classical Cepheids) stellar populations. The characterization of these variables offers a unique opportunity to probe star formation through the ages, in the primitive environment provided by VV124, largely unperturbed by external influences.

Speaker: Massimo Marengo (Florida State University)

All 2023 Spring Colloquium talks are held on Wednesdays at 3:00 PM.  You may join the colloquium in person at STScI’s John N. Bahcall Auditorium or virtually or at the links listed below. 

• Facebook Link: https://www.facebook.com/STScILiveScienceEvents
• Live Captioning Link: https://www.streamtext.net/player?event=STSI-ColloqiumSeries

Please direct questions or comments to contact above. The Spring Colloquium Committee members are: JHU Members: Kevin Schlaufman, Co-Chair, Ethan Vishniac, Arshia Jacob and STScI Members: Joel Green, Co-chair, Armin Rest, Co-chair and Andreea Petric.