D'Odorico, V.Cristiani, S.Pomante, E.Carswell, R. F.Viel, MatteoBarai, P.Becker, G. D.Calura, F.Cupani, G.Fontanot, F.Haehnelt, M. G.Kim, T.-S.Miralda Escudé, JordiRorai, A.Tescari, E.Vanzella, E.2018-01-242018-01-242016-08-260035-8711https://hdl.handle.net/2445/119259In this work, we investigate the abundance and distribution of metals in the intergalactic medium (IGM) at 〈z〉 ≃ 2.8 through the analysis of an ultra-high signal-to-noise ratio UVES spectrum of the quasar HE0940-1050. In the C IV forest, our deep spectrum is sensitive at 3σ to lines with column density down to log NCIV ≃ 11.4 and in 60 per cent of the considered redshift range down to ≃11.1. In our sample, all H I lines with log NHI ≥ 14.8 show an associated C IV absorption. In the range 14.0 ≤ log NHI < 14.8, 43 per cent of H I lines has an associated C IV absorption. At log NHI < 14.0, the detection rates drop to <10 per cent, possibly due to our sensitivity limits and not to an actual variation of the gas abundance properties. In the range log NHI ≥ 14, we observe a fraction of H I lines with detected C IV a factor of 2 larger than the fraction of H I lines lying in the circumgalactic medium (CGM) of relatively bright Lyman-break galaxies hosted by dark matter haloes with 〈M〉 ∼ 1012 M⊙. The comparison of our results with the output of a grid of photoionization models and of two cosmological simulations implies that the volume filling factor of the IGM gas enriched to a metallicity logZ/Z⊙≳−3 log⁡Z/Z⊙≳−3 should be of the order of ∼10-13 per cent. In conclusion, our results favour a scenario in which metals are found also outside the CGM of bright star-forming galaxies, possibly due to pollution by lower mass objects and/or to an early enrichment by the first sources.18 p.application/pdfeng(c) D'Odorico, V. et al., 2016GalàxiesQuàsarsCosmologiaGalaxiesQuasarsCosmologyinfo:eu-repo/semantics/article6694472018-01-24info:eu-repo/semantics/openAccess