Cosmic Origins
Searching for answers about our universe and its origins

Galaxies Science Interest Group
(Galaxies SIG)

Galaxies SIG Events

Understanding the Production and Escape of Ionizing Photons – Far-UV Science with HWO

17 April 2024, 1:00pm ET
Anne Jaskot

JWST is transforming our knowledge of galaxy properties at z > 6, but one property it cannot observe is the emission of ionizing, Lyman Continuum (LyC) photons from these galaxies. At high redshifts, these LyC photons are absorbed by the IGM en route to Earth. Yet studying LyC radiation is critical to understand how galaxies reionized the IGM and how massive stars affect their host galaxy’s ISM. We need to know how LyC radiation is produced within galaxies and with what energies, what processes enable its escape into the IGM, and how much LyC radiation escapes from different types of galaxies. Recent LyC observations of low-redshift galaxies with HST have begun to answer these questions but are limited to moderately bright (MUV -18 to -21) galaxies at z ~ 0.3 with limited spatial information. I will review what we’ve learned from these HST observations as well as the open questions that remain. I will discuss how future FUV science with HWO at higher spatial resolution, higher sensitivity, or shorter wavelengths could provide important insights into low-metallicity super star clusters, their effects on the ISM, and the reionization of the universe.

Session Video

10 May 2024
JWST Senior Project Scientist Awarded Presidential Medal of Freedom
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AGN SIG – X-ray and Far IR Probe Panel Discussion | Tuesday, May 14th , 12:00pm ET
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Call for Community Input into the TESS Extended Mission Planning
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Astrophysics Technology Gaps Public Webinar | May 14th, 2024 2:00 – 3:00pm ET
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Diffuse Gas in Cosmic Ecosystems Science Interest Group (DGCE SIG) | May 23rd , 2024 – 4:00pm ET / 1:00pm PT
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