Astronomy & Astrophysics Seminar

Speaker: Dan Weisz, University of California, Berkeley

Title: The Lowest-Mass Galaxies In the Early Universe: Insights from the Local Group

Refreshments available.

Date: Wed, 26 Sep 2018, 1:30 pm – 2:30 pm
Type: Seminar
Location: 1400 BPS Bldg.

Abstract:
The Local Group is home to ∼100 galaxies less mas­sive than the Small Magel­lanic Cloud (108 Msun). Such low-mass galaxies have be­come increasing­ly rele­vant to a broad range of astro­physics from cos­mic re­ioni­za­tion to de­cipher­ing the na­ture of dark mat­ter. Yet, they are simp­ly too faint to be direct­ly detect­ed at any ap­preci­able red­shift, com­promising our ability to place them into a cosmo­logi­cal con­text. In this talk, I will de­scribe how ob­serva­tions of resolved stel­lar popula­tions in Local Group galaxies en­able the measure­ment of de­tailed star forma­tion histo­ries, which pro­vide the only avenue for tracing the evolu­tion of low-mass galaxies across cos­mic time. I will re­view our cur­rent know­ledge of low-mass galaxy evolu­tion over 6 decades in stel­lar mass, with a par­ticular em­phasis on the very ear­ly Uni­verse. I will illus­trate how local and high-red­shift galaxy ob­serva­tions can be used in tan­dem to im­prove our under­stand­ing of cos­mic re­ioniza­tion, and will con­clude by dis­cussing pros­pects for in­creased syner­gy be­tween near-field and far-field galaxy studies in the JWST era.