TY - JOUR
T1 - Outside the Lyman-break box
T2 - Detecting Lyman continuum emitters at 3.5 < z < 5.1 with CLAUDS
AU - Meštrić, U.
AU - Ryan-Weber, E. V.
AU - Cooke, J.
AU - Bassett, R.
AU - Sawicki, M.
AU - Faisst, A. L.
AU - Kakiichi, K.
AU - Inoue, A. K.
AU - Rafelski, M.
AU - Prichard, L. J.
AU - Arnouts, S.
AU - Moutard, T.
AU - Coupon, J.
AU - Golob, A.
AU - Gwyn, S.
N1 - Funding Information:
This work is based on observations taken by the 3DHST Treasury Program (HST-GO-12177 and HST-GO-12328) with the NASA/ESA HST, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.
Publisher Copyright:
© 2020 The Author(s).
PY - 2020/6/1
Y1 - 2020/6/1
N2 - Identifying non-contaminated sample of high-redshift galaxies with escaping Lyman continuum (LyC) flux is important for understanding the sources and evolution of cosmic reionization. We present CLAUDS (CFHT Large Area u-band deep survey) u-band photometry of the COSMOS field to probe LyC radiation from spectroscopically confirmed galaxies at z ≥ 3.5 and outside the standard Lyman-break galaxy colour-selection expectations. Complementary to the CLAUDS data, we use Subaru multifilter photometry, Hubble Space Telescope (HST) multifilter imaging, and the spectroscopic surveys D10K, VUDS, and 3D-HST. We present a sample of Lyman continuum galaxy (LCG) candidates in the redshift range 3.5 ≥ z ≥ 5.1. Here, we introduce 5 LCG candidates, where two are flagged quality 1 and three quality 2. The estimated fabsesc for quality 1 candidates are in the range 5 - 73 per cent and 30 - 93 per cent . These estimates are based on our derived parameters from individual galaxies as inputs to a range of BPASS models as well as mean intergalactic medium (IGM) and maximal intergalactic and circumgalactic media (IGM+CGM) transmission. We conclude that our search for LCGs is most likely biased to lines of sight with low H i densities or free from Lyman limit systems. Our two best LCG candidates have EW (Lyα) ≤ 50 Å and we find no correlation or anticorrelation between EW (Lyα), fabsesc, and Robs, the ratio of ionizing to non-ionizing observed flux in the measured passbands. Stacking candidates without solid LyC detections (S/N < 3) results in an estimated fabsesc from galaxies not greater than 1 per cent.
AB - Identifying non-contaminated sample of high-redshift galaxies with escaping Lyman continuum (LyC) flux is important for understanding the sources and evolution of cosmic reionization. We present CLAUDS (CFHT Large Area u-band deep survey) u-band photometry of the COSMOS field to probe LyC radiation from spectroscopically confirmed galaxies at z ≥ 3.5 and outside the standard Lyman-break galaxy colour-selection expectations. Complementary to the CLAUDS data, we use Subaru multifilter photometry, Hubble Space Telescope (HST) multifilter imaging, and the spectroscopic surveys D10K, VUDS, and 3D-HST. We present a sample of Lyman continuum galaxy (LCG) candidates in the redshift range 3.5 ≥ z ≥ 5.1. Here, we introduce 5 LCG candidates, where two are flagged quality 1 and three quality 2. The estimated fabsesc for quality 1 candidates are in the range 5 - 73 per cent and 30 - 93 per cent . These estimates are based on our derived parameters from individual galaxies as inputs to a range of BPASS models as well as mean intergalactic medium (IGM) and maximal intergalactic and circumgalactic media (IGM+CGM) transmission. We conclude that our search for LCGs is most likely biased to lines of sight with low H i densities or free from Lyman limit systems. Our two best LCG candidates have EW (Lyα) ≤ 50 Å and we find no correlation or anticorrelation between EW (Lyα), fabsesc, and Robs, the ratio of ionizing to non-ionizing observed flux in the measured passbands. Stacking candidates without solid LyC detections (S/N < 3) results in an estimated fabsesc from galaxies not greater than 1 per cent.
KW - dark ages
KW - first stars
KW - galaxies: High-redshift
KW - galaxies: Photometry
KW - reionization
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U2 - 10.1093/mnras/staa920
DO - 10.1093/mnras/staa920
M3 - Article
AN - SCOPUS:85094619010
VL - 494
SP - 4986
EP - 5007
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 4
ER -