Evolution in the bias of faint radio sources to z ~ 2.2
Evolution in the bias of faint radio sources to z ~ 2.2
复制标题
微弱射电源的偏差向 z ~ 2.2 的演变
DOI：
10.1093/mnras/stu453
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发表时间：
2014
影响因子：
4.8
通讯作者：
Lindsay S
中科院分区：
文献类型：
--
作者：
Lindsay S
量化重子物质如何追踪暗物质的分布，是理解星系形成和我们约束宇宙学模型的关键。利用射电星系和近红外星系的互相关函数，我们对射电星系toz2.2进行了大尺度聚类分析。利用VISTA深河外星系观测（VIDEO-XMM 3）和加拿大-法国-夏威夷望远镜遗产巡天（CFHTLS）测光方法，在近红外和光学波段测量了Ks<23.5星系的角自相关函数，测量的星系的光度红移为4。然后利用这些源与S1.4>90μJy的766个射电源的互相关函数，推断了4个红移仓中射电星系的线性偏差。我们发现，在λ = 0.3时，b = 0.57 ± 0.06，在λ = 2.2时，b = 8.55 ± 3.11。此外，我们将射电源分成子样本，以确定偏差如何取决于射电光度，并发现偏差明显高于Wilman等人的模拟预测，并且与较低亮度但更丰富的FR-I群体一致，其具有与高亮度但罕见的FR-II类似的偏差。我们的结果表明，更高的质量，特别是FR-I源比在模拟中假设的，特别是对更高的红移。
Quantifying how the baryonic matter traces the underlying dark matter distribution is key to both understanding galaxy formation and our ability to constrain the cosmological model. Using the cross-correlation function of radio and near-infrared galaxies, we present a large-scale clustering analysis of radio galaxies toz∼ 2.2. We measure the angular auto-correlation function of Ks<23.5 galaxies in the VISTA Deep Extragalactic Observations (VIDEO-XMM3) field with photometric redshifts out toz= 4 using VIDEO and CFHTLS (Canada–France–Hawaii Telescope Legacy Survey) photometry in the near-infrared and optical. We then use the cross-correlation function of these sources with 766 radio sources at S1.4>90μJy to infer linear bias of radio galaxies in four redshift bins. We find that the bias evolves fromb= 0.57 ± 0.06 atz∼ 0.3 to 8.55 ± 3.11 atz∼ 2.2. Furthermore, we separate the radio sources into subsamples to determine how the bias is dependent on the radio luminosity, and find a bias which is significantly higher than predicted by the simulations of Wilman et al., and consistent with the lower luminosity but more abundant FR-I population having a similar bias to the highly luminous but rare FR-IIs. Our results are suggestive of a higher mass, particularly for FR-I sources than assumed in simulations, especially towards higher redshift.