Dr. Clara Martínez-Vázquez, Science Fellow, Gemini Observatory / NSF’s NOIRLab
When
Where
Abstract: Pulsating variable stars play a major role in the study of stellar populations and in cosmology, as their pulsation properties are traditionally used to determine distances and to put constraints on stellar physical properties. Depending on the mass of the star, the pulsation occurs at a particular evolutive phase. Therefore different types of pulsating variable stars are linked to stellar populations of given ages of the systems they belong to, providing information about the properties of the underlying population and a way to study their galactic structure, star-formation history and evolution. The most frequent and common pulsating stars found among Local Group dwarf galaxies are RR Lyrae (RRL) stars. The enormous amount of detections of RRL stars in surveys like ASAS, Catalina, DES, Gaia, OGLE, PanSTARRS, ZTF (and the future Vera C. Rubin LSST), and the fact that RRL stars are stellar tracers of old stellar populations (>10 Gyr) makes them powerful archaeological tools. In this talk, I will show how RRL stars have been used to detect/confirm new ultra-faint and ultra-diffuse dwarf galaxies and to obtain accurate distances to those systems. I will also show how, in those systems where the rate of RRL stars is large enough, RRL stars can be used as metallicity tracers and provide insight into the chemical evolution of the old population of their host system.
In addition, I will review studies based on the population of classical and anomalous Cepheids (young and intermediate-age population) in dwarf galaxies with recent star-formation history, and show that the relative frequency of anomalous Cepheids is different in old dwarf galaxies and galaxies with large intermediate-age populations.
Finally, I will provide insights on future works in the field of short pulsating stars (such as RRL stars) and long period variables (such as Miras) using NOIRLab facilities.
Virtual-Only