The Spectral Evolution of the First Galaxies. III. Simulated James Webb Space Telescope Spectra of Reionization-epoch Galaxies with Lyman-continuum Leakage

Erik Zackrisson, Christian Binggeli, Kristian Finlator, Nickolay Y. Gnedin, Jan-Pieter Paardekooper, Ikkoh Shimizu, Akio K. Inoue, Hannes Jensen, Genoveva Micheva, Sadegh Khochfar, Claudio Dalla Vecchia

Research output: Contribution to journalArticlepeer-review

Abstract

Using four different suites of cosmological simulations, we generate synthetic spectra for galaxies with different Lyman-continuum escape fractions (f esc) at redshifts z≈ 7-9, in the rest-frame wavelength range relevant for the James Webb Space Telescope (JWST) NIRSpec instrument. By investigating the effects of realistic star formation histories and metallicity distributions on the EW(Hβ)-β diagram (previously proposed as a tool for identifying galaxies with very high f esc), we find that neither of these effects are likely to jeopardize the identification of galaxies with extreme Lyman-continuum leakage. Based on our models, we expect that essentially all z≈ 7{--}9 galaxies that exhibit rest-frame {EW}({{H}}β )≲ 30 Å to have {f}{esc}> 0.5. Incorrect assumptions concerning the ionizing fluxes of stellar populations or the dust properties of z> 6 galaxies can in principle bias the selection, but substantial model deficiencies of this type should at the same time be evident from offsets in the observed distribution of z> 6 galaxies in the EW(Hβ)-β diagram compared to the simulated distribution. Such offsets would thereby allow JWST/NIRSpec measurements of these observables to serve as input for further model refinement.
Original languageEnglish
Pages (from-to)78
JournalAstrophysical Journal
Volume836
Issue number1
DOIs
Publication statusPublished - 9 Feb 2017

Keywords

  • dark ages
  • reionization
  • first stars
  • galaxies: high-redshift
  • techniques: spectroscopic

Fingerprint

Dive into the research topics of 'The Spectral Evolution of the First Galaxies. III. Simulated James Webb Space Telescope Spectra of Reionization-epoch Galaxies with Lyman-continuum Leakage'. Together they form a unique fingerprint.

Cite this