E-XQR-30: The evolution of MgII, CII and OI across 2
Autor: Sebastian, Alma Maria, Ryan-Weber, Emma, Davies, Rebecca L., Becker, George D., Keating, Laura C., D'Odorico, Valentina, Meyer, Romain A., Bosman, Sarah E. I., Cupani, Guido, Kulkarni, Girish, Haehnelt, Martin G., Lai, Samuel, Eilers, Anna-Christina, Bischetti, Manuela, Gallerani, Simona
Rok vydání: 2024
Předmět:
Druh dokumentu: Working Paper
Popis: Intervening metal absorbers in quasar spectra at $z > 6$ can be used as probes to study the chemical enrichment of the Universe during the Epoch of Reionization (EoR). This work presents the comoving line densities ($dn/dX$) of low ionisation absorbers, namely, Mg II (2796\r{A}), C II (1334\r{A}) and O I (1302\r{A}) across $2 0.03$\r{A}. For the first time, we present the comoving line densities of 131 weak ($W < 0.3$\r{A}) intervening Mg II absorbers at $1.9 < z < 6.4$ which exhibit constant evolution with redshift similar to medium ($0.3 < W < 1.0$\r{A}) absorbers. However, the cosmic mass density of Mg II - dominated by strong Mg II systems - traces the evolution of global star formation history from redshift 1.9 to 5.5. E-XQR-30 also increases the absorption path length by a factor of 50% for C II and O I whose line densities show a rising trend towards $z > 5$, in agreement with previous works. In the context of a decline in metal enrichment of the Universe at $z > 5$, the overall evolution in the incidence rates of absorption systems can be explained by a weak - possibly soft fluctuating - UV background. Our results, thereby, provide evidence for a late reionization continuing to occur in metal-enriched and therefore, biased regions in the Universe.
Comment: 20 pages, 21 figures
Databáze: arXiv
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