2025/07/15 by Yuting Liu, Liu, Y., Sara Mascia +37
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2507.11045
Identifying Lyman continuum (LyC) leakers at intermediate redshifts is crucial for understanding the properties of cosmic reionizers, as the opacity of the intergalactic medium (IGM) prevents direct detection of LyC emission from sources during the Epoch of Reionization (EoR). In this study, we confirm two new LyC candidate leakers at z ∼ 3 in the Abell 2744 cluster field, with absolute escape fractions (fesc) of 0.90+0.07-0.86 and 0.60+0.37-0.56, respectively. The LyC emission was detected using HST/WFC3/F275W and F336W imaging. These two candidate leakers appear faint ( MUV = -18.1 ± 0.1 and -17.81 ± 0.11), exhibit blue UV continuum slopes (β= -2.42 ± 0.05 and -1.78 ± 0.19), have low masses (M_⋆ ∼ 107.73 ± 0.1 and 107.07 ± 0.05 M_\odot) and show \lya equivalent widths of 90 ± 3 Å and 28 ± 12 Å, respectively. The discovery of these two LyC candidate leakers was achieved in a catalog of 91 spectroscopically confirmed sources using JWST and/or MUSE public spectra. We also analyze properties that have been proposed as indirect indicators of LyC emission, like \lya, O32 ratio, and M_⋆: we create subsample of galaxies selected according to such properties, stack the LyC observations of these subsample and assess the limits in escape fractions in the stacks. By analysing the individual candidates and the stacks, in the context of the currently limited sample of known LyC leakers at z ∼ 3, we aim to enhance our understanding of LyC escape mechanisms and improve our predictions of the LyC fesc during the EoR.