Metals in the z ~ 3 intergalactic medium: results from an ultra-high signal-to-noise ratio UVES quasar spectrum
Metals in the z ~ 3 intergalactic medium: results from an ultra-high signal-to-noise ratio UVES quasar spectrum
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z ~ 3 星际介质中的金属：超高信噪比 UVES 类星体光谱的结果
DOI：
10.1093/mnras/stw2161
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发表时间：
2016
影响因子：
4.8
通讯作者：
D'Odorico V
中科院分区：
文献类型：
--
作者：
D'Odorico V
在这项工作中，我们通过对类星体≃的超高信噪比UVES光谱的分析，研究了星际介质中金属的丰度和分布。在文明森林，我们的深光谱在3σ处对柱密度降至logNCIV≃11.4的线敏感，并在所考虑的红移范围的60%降至≃11.1。在我们的样本中，所有具有logNHI≥14.8的希林都显示了相关的Civ吸收。在14.0LogNHI<；14.8%的≤范围内，43%的Hilines具有相关的Civ吸收。在logNHI<；14.0，检测率降至10%，这可能是由于我们的灵敏度限制，而不是由于气体丰度属性的实际变化。在射程LogNHI≥14中，我们观测到了一小部分希尔线，其CIVA因子大于位于相对明亮的莱曼破裂星系的围星系介质中的希尔线的比例，这些星系由暗物质晕托管，具有<；M>；∼1012M⊙。我们的结果与光电离模型网格和两个宇宙学模拟的结果相比较表明，浓缩到金属的IGM气体的体积填充因子应该在∼10%-13%的量级。总而言之，我们的结果倾向于一种假设，即在明亮的恒星形成星系的CGM之外也发现了金属，这可能是由于较低质量天体的污染和/或第一源的早期浓缩。
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 Civforest, our deep spectrum is sensitive at 3σ to lines with column density down to logNCIV≃ 11.4 and in 60 per cent of the considered redshift range down to ≃11.1. In our sample, all Hilines with logNHI≥ 14.8 show an associated Civabsorption. In the range 14.0 ≤ logNHI< 14.8, 43 per cent of Hilines has an associated Civabsorption. At logNHI< 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 logNHI≥ 14, we observe a fraction of Hilines with detected Civa factor of 2 larger than the fraction of Hilines lying in the circumgalactic medium (CGM) of relatively bright Lyman-break galaxies hosted by dark matter haloes with <M> ∼ 1012M⊙. 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 metallicityshould 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.