论文标题
用C IV森林相关函数来限制IgM富集和金属性
Constraining IGM enrichment and metallicity with the C IV forest correlation function
论文作者
论文摘要
弥漫间层间培养基（IGM）中金属的生产和分布对星系形成模型和BARYON（RE）循环过程具有影响。高电离状态和低离子化状态中金属的相对丰度也被认为对宇宙的电离历史敏感。但是，Z〜4时IgM背景金属性的测量值很少，并且彼此之间的吻合差，并且近IR渲染的灵敏度降低，几乎不可能检测到单个金属吸收剂。我们提出了一种新的基于聚类的技术，该技术可以通过在所有光谱像素上平均统计平均来检测这些弱IgM吸收器，此处应用于C IV林。我们使用不同模型的不均匀金属分布模拟Z = 4.5 IgM，并使用C IV林的模拟串来研究其两点相关函数（2pcf）。 2PCF在C IV线的双重分离处表现出明显的峰值。峰值幅度与金属性四倍地尺度，而富集形态则影响2PCF的形状和振幅。富集拓扑的效果也可以根据金属质量和体积填充因子而构建，我们将它们的趋势显示为富集拓扑的函数。对于与Z〜3金属分布一致的模型，我们发现我们可以将[C/H]限制为0.2 DEX，log $ \，m _ {\ rm {min}} $在0.4 dex之内，而$ r $在15％以内。我们表明，可以轻松地识别和掩盖星系的圆形培养基引起的强吸收器，从而使人们能够恢复基础的IgM信号。金属线森林的自动相关提出了一条新的诱人途径，同时限制IgM金属性和富集拓扑，在Z> 4时高精度，从而将此类测量方法推入了电源时期。
The production and distribution of metals in the diffuse intergalactic medium (IGM) have implications for galaxy formation models and the baryon (re)cycling process. The relative abundance of metals in high versus low-ionization states has also been argued to be sensitive to the Universe's reionization history. However, measurements of the background metallicity of the IGM at z~4 are sparse and in poor agreement with one another, and reduced sensitivity in the near-IR renders detecting individual metal absorbers nearly impossible. We present a new clustering-based technique that enables the detection of these weak IGM absorbers by statistically averaging over all spectral pixels, here applied to the C IV forest. We simulate the z=4.5 IGM with different models of inhomogeneous metal distributions and investigate its two-point correlation function (2PCF) using mock skewers of the C IV forest. The 2PCF demonstrates a clear peak at the doublet separation of the C IV line. The peak amplitude scales quadratically with metallicity, while enrichment morphology affects both the shape and amplitude of the 2PCF. The effect of enrichment topology can also be framed in terms of the metal mass- and volume-filling factors, and we show their trends as a function of the enrichment topology. For models consistent with the distribution of metals at z~3, we find that we can constrain [C/H] to within 0.2 dex, log$\,M_{\rm{min}}$ to within 0.4 dex, and $R$ to within 15%. We show that strong absorbers arising from the circumgalactic medium of galaxies can be easily identified and masked, allowing one to recover the underlying IGM signal. The auto-correlation of the metal-line forest presents a new and compelling avenue to simultaneously constrain IGM metallicity and enrichment topology with high precision at z>4, thereby pushing such measurements into the Epoch of Reionization.
