Resumo

GARCIA, L. A.  e  RYAN-WEBER, E. V.. Can UVB Variations Reconcile Simulated Quasar Absorption Lines at High Redshift?. Rev. mex. astron. astrofis [online]. 2020, vol.56, n.1, pp.97-111.  Epub 19-Mar-2021. ISSN 0185-1101.  https://doi.org/10.22201/ia.01851101p.2020.56.01.11.

In this work we present new calculations of the observables associated with synthetic metal and HI absorption lines in the spectra of high redshift quasars, inspired by questions and limitations raised in work with a uniform Haardt-Madau 2012 ultraviolet background (UVB). We introduce variations at z ≈ 6 to the UVB and HI self-shielding and explore the sensitivity of the absorption features to modifications of the hardness of the UVB. We find that observed SiIV and low ionization states (e.g. CII, SiII, OI) are well represented by a soft UV ionizing field at z = 6, but this same prescription, fails to reproduce the statistical properties of the observed CIV ion absorber population. We conclude that small variations in the UVB (not greater than a dex below Haardt-Madau 2012 emissivity at 1 Ryd) and HI SSh at z ≈ 6 play a major role in improving the estimation of metal ions and HI statistics at high z.

Palavras-chave : cosmology: theory-dark ages; reionization, first stars; intergalactic medium; methods: numerical; quasars: absorption lines.

        · resumo em Espanhol     · texto em Inglês     · Inglês ( pdf )