A Lyman continuum analysis of $\sim 100$ galaxies at $z_{\mathrm{spec}}\sim 3$ in the Abell 2744 cluster field

Liu, Y. (author), Bradač, Maruša (author)

Identifying Lyman continuum (LyC) leakers at intermediate redshifts is crucial for understanding the properties of cosmic reionizers because the opacity of the intergalactic medium (IGM) prevents the direct detection of LyC emission from sources during the Epoch of Reionization (EoR). In this study, we confirm two new LyC candidate leakers at ▫$z \sim 3$▫ in the Abell 2744 cluster field, with absolute escape fractions ▫$(f_{\text{esc}})$▫ of ▫$0.83_{-0.80}^{+0.15}$▫ and ▫$0.74_{-0.70}^{+0.23}$▫, respectively. The LyC emission was detected using HST/WFC3/F275W and F336W imaging. These two candidate leakers appear to be faint (▫$M_{\text{UV}} = -17.61 \pm 0.06$▫ and ▫$-18.22 \pm 0.10$▫), exhibit blue UV continuum slopes (▫$\beta = - 2.43 \pm 0.05$▫ and ▫$-1.92 \pm 0.09$▫), have low masses (▫$M_{\ast} \sim 10^{7.51 \pm 0.03}$▫ and ▫$10^{7.17 \pm 0.15}\ M_{\ast}$▫) and Ly▫$\alpha$▫ equivalent widths of ▫$90 \pm 3$▫ Å and ▫$28 \pm 12$▫ Å, respectively. These two LyC candidate leakers were detected in a catalog of 91 spectroscopically confirmed sources using public spectra from the JWST and/or MUSE. We also analyzed properties that were proposed as indirect indicators of LyC emission, such as Ly▫$\alpha$▫, the O32 ratio, and ▫$M_{\ast}$▫. We created a galaxy subsample that was selected according to these properties, stacked the LyC observations of this subsample, and assessed the limits of the escape fractions in the stacks. We aim to enhance our understanding of LyC escape mechanisms and improve our predictions of the LyC ▫$f_{\text{esc}}$▫ during the EoR by analyzing the individual candidates and the stacks in the context of the currently limited sample of known LyC leakers at ▫$z \sim 3$▫.

• Language: English
• Keywords: galaxy evolution, high-redshift galaxies, star formation
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 12 str.
• Numbering: Vol. 704, art. no. A328
• PID: 20.500.12556/RUL-181938
• UDC: 524.8
• ISSN on article: 1432-0746
• DOI: 10.1051/0004-6361/202556410
• COBISS.SI-ID: 275775747
• Publication date in RUL: 20.04.2026

Record is a part of a journal

• Title: Astronomy & astrophysics
• Shortened title: Astron. astrophys.
• Publisher: EDP Sciences
• ISSN: 1432-0746
• COBISS.SI-ID: 392577

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: galaksije, rdeči premik, nastanek zvezd, nastanek galaksij