Using a sample of galaxies at z ≈ 3 with detected Lyman Continuum (LyC) leakage in the SSA22 field, we attempt to verify a proposed indirect method for identifying cases with high LyC escape fraction fesc based on measurements of the Hβ equivalent width (EW) and the β slope of the UV continuum. To this end, we present Keck/MOSFIRE Hβ emission line flux measurements of LyC galaxies (LCGs) at spectroscopic redshifts zspec ∼ 3.3, Lyman break galaxies (LBGs) at photometric redshifts zphot = 2.7-3.7, and Lyα emitters at zphot = 3.1. We also reconfirm the spectroscopic redshifts and measure the Hβ emission line fluxes from 2 LCGs and 6 LBGs. For the LCG in our sample with the most extreme fesc, as revealed by the direct detection of LyC photons, we find that the EW(Hβ)-β method gives a broadly consistent estimate for fesc, although the error bars remain very large. We also discuss how a combination of fesc measurements based on direct and indirect methods can shed light on the LyC escape mechanism and the anisotropy of the leakage.
|Publication status||Published - 2020 Mar 8|
- Galaxies: high-redshift
- Galaxies: ISM
- Galaxies: starburst
ASJC Scopus subject areas