A Cautionary Tale of LyC Escape Fraction Estimates from High Redshift Galaxies
R. Bassett, E.V. Ryan-Weber, J. Cooke, U. Mestric, L.J. Prichard, M., Rafelski, I. Iwata, M. Sawicki, S. Gwyn, S. Arnouts

TL;DR
This paper introduces a new methodology for estimating the LyC escape fraction from high-redshift galaxies, accounting for uncertainties and IGM transmission variability, and demonstrates its limitations and biases in current observational approaches.
Contribution
It presents a novel Bayesian method for deriving the posterior distribution of LyC escape fractions considering IGM transmission uncertainties, and critically evaluates existing estimation techniques and galaxy selection biases.
Findings
The new method provides a more accurate posterior distribution of $f_{esc}$.
Average transmission assumptions can significantly overestimate $f_{esc}$.
Photometric redshift overestimations bias LyC candidate selection.
Abstract
Measuring the escape fraction, , of ionizing, Lyman Continuum (LyC) radiation is key to our understanding of the process of cosmic reionization. In this paper we provide a methodology for recovering the posterior probability distribution of the LyC escape fraction, , considering both the observational uncertainties and ensembles of simulated transmission functions through the intergalactic medium (IGM). We present an example of this method applied to a VUDS galaxy at and find = 0.51 and compare this to the values computed assuming averaged IGM transmission with and without consideration of detection bias along average sightlines yielding = 1.40, and = 0.82. Our results highlight the limitations of methods…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
