Caltech/IPAC Seminar

The far-ultraviolet (FUV) provides a unique window into recent star formation, the extragalactic background light, and the escape of ionizing radiation from galaxies. In this talk, I will introduce the Far-Ultraviolet Extragalactic Legacy (FUEL) Survey, which brings together 365 orbits of archival Hubble Space Telescope imaging across the GOODS-S, GOODS-N, and COSMOS fields. By addressing challenging instrumental backgrounds and producing uniformly processed FUV mosaics and source catalogs, the survey provides a new resource for studying galaxies and the ultraviolet sky.

I will present our latest results using the FUEL Survey to measure faint FUV galaxy number counts and constrain the galaxy contribution to the FUV extragalactic background light. I will then discuss how these deep observations allow us to revisit previously reported Lyman-continuum (LyC) emitters. Six candidate detections are not confirmed by deeper Hubble imaging, highlighting the challenges of identifying escaping ionizing radiation.

Finally, I will outline our ongoing and future investigations, including a stacking analysis of galaxies at z ~ 1.3 to constrain their average LyC escape fractions, and an investigation into the origin of an additional, nearly uniform FUV background component identified during the survey reduction. Together, these studies demonstrate how archival Hubble observations can provide new insights into galaxy evolution and the ultraviolet background.