Galaxy Evolution at the Faint-End of the Luminosity Function, with a Highlight from JWST Results on Resolved Stars
Prof. Kristy McQuinn
Department of Physics and Astronomy
Rutgers University
Small galaxies are key tools for understanding structure formation and galaxy evolution. Traditionally defined as galaxies below a mass threshold of ~10^9 Msun, they have long been used to study the individual components of galaxies (stars, gas, chemical elements) and are also used as tests of our cosmological models. We are now finding small galaxies in our Local Group with Mstar as low as 10^3 Msun and gas-rich, star-forming galaxies at slightly farther distances with Mstar ~10^5-10^7 Msun. These extremely low-mass systems approach regimes where theoretical predictions of their physical properties begin to diverge based on different assumptions of their baryonic and dark matter physics and in reionization models. As such, these galaxies can be used to explore questions about galaxy formation, survival, and evolution.
In this talk, I will (i) show recent results characterizing gas-rich, star-forming galaxies to lower masses, with constraints on the changing baryon-to-dark matter ratio in small galaxies, (ii) discuss the newly discovered Local Group galaxy, Pegasus W, which has properties that challenge our models, and (iii) highlight work on JWST imaging of resolved stars in nearby systems.
Hosted by Prof. Kirby
Originally published at physics.nd.edu.