Login | STScI Home | HubbleSite | Copyright, Content Use, and Policies
STScI Webcast

2019 Cool Sci @ STScI

Unlocking Reionization: Keys from Low Redshift Analog Galaxies

Presented by: Alaina Henry  (STScI)
Category: Science Colloquia   Duration: 30 minutes   Broadcast date: January 23, 2019
  • Bookmark/Share

Abstract: Presently, little is known about the detailed history of the reionization. While JWST is expected to uncover unprecedented populations of galaxies in the early universe, there are key questions that it will not address-- namely, how do UV Lyman Continuum (LyC) photons escape galaxies to ionize the IGM? Fortunately, in recent years, populations of low redshift objects with stellar and nebular properties similar to galaxies at high-redshifts have been identified in the SDSS. Spectroscopic followup observations with HST/COS have opened up new windows into their absorbing ISM: strong Lyman Alpha emission is common, and ionizing radiation has been found to escape in some surprising cases. In this talk, I will review how UV ISM spectroscopy helps us to understand the gas that regulates LyC output. I will discuss future prospects involving newly planned observations, as well tests for new LyC diagnostics. Finally, I will show how improvements to resonant-line radiation transport modeling of Lyman Alpha and metal lines may unlock the physical conditions in the ISM and CGM, where the escape of LyC is determined.