Title:
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Metals in the z ∼ 3 intergalactic medium: results from an ultra-high signal-to-noise ratio UVES quasar spectrum
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Author:
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D'Odorico, V.; Cristiani, S.; Pomante, E.; Carswell, R. F.; Viel, M.; Barai, P.; Becker, G. D.; Calura, F.; Cupani, G.; Fontanot, F.; Haehnelt, M. G.; Kim, T.-S.; Miralda Escudé, Jordi; Rorai, A.; Tescari, E.; Vanzella, E.
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Other authors:
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Universitat de Barcelona |
Abstract:
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In 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 logZ/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. |
Subject(s):
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-Galàxies -Quàsars -Cosmologia -Galaxies -Quasars -Cosmology |
Rights:
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(c) D'Odorico, V. et al., 2016
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Document type:
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Article Article - Published version |
Published by:
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Royal Astronomical Society
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