Metals in the z ∼ 3 intergalactic medium: results from an ultra-high signal-to-noise ratio UVES quasar spectrum

D'ODORICO, ValentinaValentinaD'ODORICOCRISTIANI, StefanoStefanoCRISTIANIPomante, E.E.PomanteCarswell, R. F.R. F.CarswellVIEL, MATTEOMATTEOVIELBarai, P.P.BaraiBecker, G. D.G. D.BeckerCalura, F.F.CaluraCUPANI, GuidoGuidoCUPANIFONTANOT, FabioFabioFONTANOTHaehnelt, M. G.M. G.HaehneltKim, T. -S.T. -S.KimMiralda-Escudé, J.J.Miralda-EscudéRorai, A.A.RoraiTescari, E.E.TescariVANZELLA, ErosErosVANZELLA2020-05-192020-05-1920160035-8711http://hdl.handle.net/20.500.12386/24975In 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 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.STAMPAenMetals in the z ∼ 3 intergalactic medium: results from an ultra-high signal-to-noise ratio UVES quasar spectrumArticle10.1093/mnras/stw21612-s2.0-85015107355000393566000032https://academic.oup.com/mnras/article/463/3/2690/2646578https://arxiv.org/pdf/1608.06116.pdf2016MNRAS.463.2690DFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation::PE9_8 Formation and evolution of galaxies