An empirical reionization history model inferred from the low-redshift Lyman continuum survey and the star-forming galaxies at z > 8

Yu Heng Lin, Claudia Scarlata, Hayley Williams, Wenlei Chen, Patrick Kelly, Danial Langeroodi, Jens Hjorth, John Chisholm, Anton M. Koekemoer, Adi Zitrin, Jose M. Diego

Research output: Contribution to journalArticlepeer-review

Abstract

We present a new analysis of the rest-frame ultraviolet (UV) and optical spectra of a sample of three z > 8 galaxies discovered behind the gravitational lensing cluster RX J2129.4+0009. We combine these observations with z > 7.5 galaxies from the literature, for which similar measurements are available. As already pointed out in other studies, the high [O iii]λ5007/[O ii]λ3727 ratios (O32) and steep UV continuum slopes (β) are consistent with the values observed for low-redshift Lyman continuum emitters, suggesting that such galaxies contribute to the ionizing budget of the intergalactic medium. We construct a logistic regression model to estimate the probability of a galaxy being a Lyman continuum emitter based on the measured MUV, β, and O32. Using this probability and the UV luminosity function, we construct an empirical model that estimates the contribution of high-redshift galaxies to reionization. The preferred scenario in our analysis shows that at z ∼8, the average escape fraction of the galaxy population [i.e. including both LyC emitters (LCEs) and non-emitters] varies with MUV, with intermediate UV luminosity (-19 < MUV < -16) galaxies having larger escape fraction. Galaxies with faint UV luminosity (-16 < MUV < -13.5) contribute most of the ionizing photons. The relative contribution of faint versus bright galaxies depends on redshift, with the intermediate UV galaxies becoming more important over time. UV bright galaxies, although more likely to be LCEs at a given log(O32) and β, contribute the least of the total ionizing photon budget.

Original languageAmerican English
Pages (from-to)4173-4182
Number of pages10
JournalMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Volume527
Issue number2
DOIs
StatePublished - 1 Jan 2024

Keywords

  • dark ages, reionization, first stars
  • galaxies: clusters: general
  • galaxies: high-redshift
  • gravitational lensing: strong

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'An empirical reionization history model inferred from the low-redshift Lyman continuum survey and the star-forming galaxies at z > 8'. Together they form a unique fingerprint.

Cite this