TY - JOUR
T1 - Testing an indirect method for identifying galaxies with high levels of Lyman continuum leakage
AU - Yamanaka, Satoshi
AU - Inoue, Akio K.
AU - Yamada, Toru
AU - Zackrisson, Erik
AU - Iwata, Ikuru
AU - Micheva, Genoveva
AU - Mawatari, Ken
AU - Hashimoto, Takuya
AU - Kubo, Mariko
N1 - Publisher Copyright:
© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2020/11/1
Y1 - 2020/11/1
N2 - 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 H β equivalent width (EW) and the β slope of the UV continuum. To this end, we present Keck/MOSFIRE H β 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 Ly α emitters at zphot = 3.1. We also reconfirm the spectroscopic redshifts and measure the H β emission-line fluxes from two LCGs and six 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(H β)-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.
AB - 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 H β equivalent width (EW) and the β slope of the UV continuum. To this end, we present Keck/MOSFIRE H β 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 Ly α emitters at zphot = 3.1. We also reconfirm the spectroscopic redshifts and measure the H β emission-line fluxes from two LCGs and six 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(H β)-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.
KW - galaxies: ISM
KW - galaxies: high-redshift
KW - galaxies: starburst
UR - http://www.scopus.com/inward/record.url?scp=85094580049&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85094580049&partnerID=8YFLogxK
U2 - 10.1093/mnras/staa2507
DO - 10.1093/mnras/staa2507
M3 - Article
AN - SCOPUS:85094580049
SN - 0035-8711
VL - 498
SP - 3095
EP - 3114
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -