• Media type: E-Article
  • Title: First measurement of the Mg ii forest correlation function in the Epoch of Reionization
  • Contributor: Tie, Suk Sien; Hennawi, Joseph F; Wang, Feige; Onorato, Silvia; Yang, Jinyi; Bañados, Eduardo; Davies, Frederick B; Oñorbe, Jose
  • Published: Oxford University Press (OUP), 2024
  • Published in: Monthly Notices of the Royal Astronomical Society, 535 (2024) 1, Seite 223-246
  • Language: English
  • DOI: 10.1093/mnras/stae2193
  • ISSN: 0035-8711; 1365-2966
  • Origination:
  • Footnote:
  • Description: ABSTRACT Strong low-ionization transitions like the Mg ii$\lambda 2796,2804$ 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 $z \ge 6.80$ quasar spectra probing the redshift range $5.96 \lt z_{\rm Mg\, {\small II}} \lt 7.42$ ($z_{\rm Mg\, {\small II}, median} = 6.47$). The correlation function exhibits strong small-scale clustering and a pronounced peak at the doublet velocity ($\Delta v = 768~{\rm km\, s^{-1}}$) 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 $[{\rm Mg/H}] \lt -3.73$ at $z_{\rm Mg\, {\small II},median} = 6.47$, assuming uninformative priors on [Mg/H] and the IGM neutral fraction $x_{\rm {H\, {\small I}}}$. Splitting the data into low-z ($5.96 \lt z_{\rm Mg\, {\small II}} \lt 6.47$; $z_{\rm Mg\, {\small II},median} = 6.235$) and high-z ($6.47 \lt z_{\rm Mg\, {\small II}} \lt 7.42$; $z_{\rm Mg\, {\small II},median} = 6.72$) subsamples again yields null detections and 95 per cent upper limits of $[{\rm Mg/H}] \lt -3.75$ and $\lt -3.45$, 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.
  • Access State: Open Access