Escape fraction estimates of EoR galaxies Virtual Observatory Resource

Authors
  1. Giovinazzo E.
  2. Oesch P.A.
  3. Weibel A.
  4. Meyer R.A.
  5. Witten C.
  6. Bhagwat A.,Brammer G.
  7. Chisholm J.
  8. de Graaff A.
  9. Gottumukkala R.
  10. Jecmen M.
  11. Katz H.,Leja J.
  12. Marques-Chaves R.
  13. Maseda M.
  14. Shivaei I.
  15. Trabitsch M.,Verhamme A.
  16. Published by
    CDS
Abstract

The escape fraction of Lyman continuum photons fesc(LyC) is the last key unknown in our understanding of cosmic reionization. Directly estimating the escape fraction (fesc) of ionizing photons in the epoch of reionization (EoR) is impossible, due to the opacity of the intergalactic medium (IGM). However, a high fesc leaves clear imprints in the spectrum of a galaxy, due to reduced nebular line and continuum emission, which also leads to bluer UV continuum slopes. Here, we exploit the large archive of deep JWST/NIRSpec spectra from the DAWN JWST Archive to analyze over 1400 galaxies at 5<z_spec_<10 and constrain their fesc based on SED fitting enhanced with a picket fence model. We identify 71 high-confidence sources with significant fesc based on Bayes factor analysis strongly favouring fesc>0 over fesc=0 solutions. We compare the characteristics of this high-escape subset against both the parent sample and established diagnostics including UVbeta slope, O32, and SFR surface density. For the overall sample, we find that most sources have a low escape fraction (<1%), however, a small subset of sources seems to emit a large number of their ionizing photons into the IGM, such that the average fesc is found to be ~10%, as needed for galaxies to drive reionization. Although uncertainties remain regarding recent burstiness and the intrinsic stellar ionizing photon output at low metallicities, our results demonstrate the unique capability of JWST/NIRSpec to identify individual LyC leakers, measure average fesc and thus constrain the drivers of cosmic reionization.

Keywords
  1. galaxies
  2. redshifted
  3. ultraviolet-astronomy
  4. line-intensities
Bibliographic source Bibcode
2026A&A...707A.352G
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/707/A352
IVOA Identifier IVOID
ivo://CDS.VizieR/J/A+A/707/A352

Access

Web browser access HTML
https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/707/A352
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/707/A352
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/707/A352
IVOA Table Access TAP
https://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/707/A352/tablea1?
https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/707/A352/tablea1?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/707/A352/tablea1?

History

2026-03-17T08:06:07Z
Resource record created
2026-03-17T07:06:31Z
Updated
2026-03-17T08:06:07Z
Created

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr