Monday Science Seminar

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4530 Sterling Hall
@ 12:00 pm - 1:00 pm

An informal seminar series to highlight work from early career researchers from institutions around the world.

Speaker: Dr. Piyush Sharda, an Oort Fellow at the Leiden Observatory

Title: Using metals to trace multi-scale structure formation in galaxies

Abstract: From the time the first stars formed to the present-day, metals have witnessed the assembly of structure in the Universe in great detail. Although metals only form in stars and stellar remnants, they are ubiquitously present everywhere — from planetary cores to the intergalactic medium. However, we still do not understand how metals are effectively dispersed throughout the Universe, and the various roles they play in shaping galaxies. In this talk, I will present a multi scale approach to study the role of metals in galaxy evolution, from molecular clouds to galactic discs. On smaller scales, I will focus on physical processes that shape up the initial mass function (IMF, with a particular emphasis on metal-free and metal-poor environments) that directly set the integrated yield of metals in the first and early galaxies. I will discuss results from high resolution radiation-magnetohydrodynamic simulations that study the impact of turbulence, radiation, and magnetic fields on the primordial IMF, and describe analytical models of dusty molecular clouds that explain the transition in the IMF as the metal abundance grows over cosmic time. On larger scales, the talk will cover the physics of gas-phase metal distribution in galaxies. Using a combination of spatially-resolved gas-phase metallicity measurements and novel semi-analytical models, I will present recent results that advance our understanding of metallicity gradients in (late type) galaxies. In particular, I will show how self-consistently incorporating metal dynamics into galaxy evolution models is key to explaining the observed trends in metallicity gradients with galaxy mass, metallicity, and kinematics. I will end by highlighting how such a multi-scale approach is necessary to study the physics of galaxy evolution at cosmic dawn that is now within the reach of JWST.

Organized by: Leon Trapman, Dan Rybarczyk, Nickolas Pingel