{"paper":{"title":"Photoionization models for extreme Ly$\\alpha$ $\\lambda$1216 and HeII $\\lambda$1640 ratios in quasar halos, and PopIII vs AGN diagnostics","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"(2) Centro de Astrobiolog\\'ia (INTA-CSIC), (3) Instituto de Astronom\\'ia, 4) ((1) Instituto de Astrof\\'isica e Ci\\^encias do Espa\\c{c}o, (4) Indian Institute of Technology Guwahati, A. Humphrey (1), CAUP, Ctra de Torrej\\'on a Ajalvir, Guwahati, India), L. Binette (3), Madrid, M\\'exico, M\\'exico D.F., M. Villar-Mart\\'in (2), Portugal, PT4150-762 Porto, R. Raj (1, Rua das Estrelas, Spain, Torrej\\'on de Ardoz, Universidade do Porto, Universidad Nacional Aut\\'onomo de M\\'exico","submitted_at":"2018-10-10T11:32:56Z","abstract_excerpt":"We explore mechanisms to produce extremely high Ly-alpha/HeII flux ratios, or to enhance the observed number of Ly-alpha photons per incident ionizing photon, in extended AGN-photoionized nebulae at high-redshift. Using photoionization models, we explore the impact of ionization parameter, gas metallicity, ionizing spectrum, electron energy distribution, and cloud viewing angle on the relative fluxes of Ly-alpha, HeII and other lines, and on the observed number of Ly-alpha photons per incident ionizing photon. We find that low ionization parameter, a relatively soft or filtered ionizing spectr"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1810.04463","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}