First Measurement of the Mg II Forest Correlation Function in the Epoch of Reionization
Strong low-ionization transitions like the Mg IIλ2796, 2804 Å doublet are believed to produce a detectable ‘metal-line forest’, if metals pollute the neutral intergalatic medium (IGM). We measure the autocorrelation of the Mg II forest transmission using 10 ground-based z ≥ 6.80 quasar spectra probi...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad de Sevilla (US) |
| Repositorio: | idUS. Depósito de Investigación de la Universidad de Sevilla |
| OAI Identifier: | oai:idus.us.es:11441/170889 |
| Acceso en línea: | https://hdl.handle.net/11441/170889 https://doi.org/10.1093/mnras/stae2193 |
| Access Level: | acceso abierto |
| Palabra clave: | Cosmology: observations Intergalactic medium Methods: observational Quasars: absorption lines |
| Sumario: | Strong low-ionization transitions like the Mg IIλ2796, 2804 Å doublet are believed to produce a detectable ‘metal-line forest’, if metals pollute the neutral intergalatic medium (IGM). We measure the autocorrelation of the Mg II forest transmission using 10 ground-based z ≥ 6.80 quasar spectra probing the redshift range 5.96 < zMg II < 7.42 (zMg II,median = 6.47). The correlation function exhibits strong small-scale clustering and a pronounced peak at the doublet velocity (Δv = 768 km s−1) arising from discrete absorbers in the circumgalactic medium of galaxies. After these strong absorbers are identified and masked the signal is consistent with noise. Our measurements are compared to a suite of models generated by combining a large hydrodynamical simulation with a seminumerical reionization topology, assuming a simple uniform enrichment model. We obtain a 95 per cent credibility upper limit of [Mg/H] < −3.73 at zMg II,median = 6.47, assuming uninformative priors on [Mg/H] and the IGM neutral fraction xH I. Splitting the data into low-z (5.96 < zMg II < 6.47; zMg II,median = 6.235) and high-z (6.47 < zMg II < 7.42; zMg II,median = 6.72) subsamples again yields null detections and 95 per cent upper limits of [Mg/H] < −3.75 and < −3.45, respectively. These first measurements set the stage for making the Mg II forest an emerging tool to precisely constrain the Universe reionization and enrichment history. |
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