2007/03/31 by Tirthankar Roy Choudhury, T. Roy Choudhury, Andrea Ferrara +1 · 3 citations
Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Demography #Galaxies: Formation, Evolution, Phenomena #Galaxy #Ionizing radiation #Irradiation #Nuclear physics #Physics #Population #Redshift #Reionization #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1745-3933.2007.00338.x
Extended discussions. Accepted to MNRAS Letters
arxiv created 2007/05/16 · openalex publication_date 2007/07/03 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract Using a reionization model simultaneously accounting for a number of experimental data sets, we investigate the nature and properties of reionization sources. Such a model predicts that hydrogen reionization starts at z≈ 15, is initially driven by metal-free (Population III) stars, and is 90 per cent complete by z≈ 8. We find that a fraction fγ > 80 per cent of the ionizing power at z≥ 7 comes from haloes of mass M < 109 M⊙ predominantly harbouring Population III stars; a turnover to a Population II dominated phase occurs shortly after, with this population, residing in M > 109 M⊙ haloes, yielding fγ≈ 60 per cent at z= 6. Using Lyman-break broad-band dropout techniques, J-band detection of sources contributing to 50 per cent (90 per cent) of the ionizing power at z∼ 7.5 requires reaching a magnitude J110,AB= 31.2 (31.7), where ∼ 15 (30) (Population III) sources arcmin−2 are predicted. We conclude that z > 7 sources tentatively identified in broad-band surveys are relatively massive (M≈ 109 M⊙) and rare objects which are only marginally (≈1 per cent) adding to the reionization photon budget.