Taking Galaxies Apart and Putting Them Back Together Again

Taking Galaxies Apart and Putting Them Back Together Again

Understanding the growth and evolution of stars and galaxies across cosmic time is a cornerstone of modern observational cosmology. After Cosmic Dawn, the first generation of galaxies powered much of cosmic re-ionization. Later, the global star-formation density accelerated toward its peak at Cosmic Noon, when most of the stellar mass in the Universe was formed. As we study the growth and evolution of stars and galaxies across cosmic time, the industry standard is to use individual galaxies as the de facto quanta unit of measure. There are practical reasons for counting galaxy-by-galaxy: galaxies grow and reside in dark matter haloes that map back to primordial mass over-densities, and even space-based observatories can only marginally resolve galaxies in the distant universe. However, the physical processes that drive galaxy growth and evolution — cloud collapse, star formation, feedback, etc. — operate on scales much smaller than a galaxy. Resolving the physical properties of stellar populations in distant galaxies requires zooming in on physical scales comparable to that on which stars form, i.e. giant molecular clouds collapsing into individual star-forming clusters and regions. I will present ongoing work using bright, strongly lensed galaxies to zoom-in on the scales of individual star clusters to resolve the physics of what’s happening inside distant galaxies.

Sebastián López
Seminar Coordinator
DAS/UChile  – slopez@das.uchile.cl