论文标题
来自21厘米强度图的大规模光环中的中性氢分布
The neutral hydrogen distribution in large-scale haloes from 21-cm intensity maps
论文作者
论文摘要
我们通过将从2DFGRS目录中选择的48,430个星系堆叠到一组21厘米的强度图上，以大规模的光环中的大规模光环中检测到中性氢（HI）径向亮度温度曲线。 z \ Lessim 0.10 $。通过在主成分分析中删除10和20前景模式来获得地图。我们在地图级别执行堆栈，并从光晕发射的圆形对称版本中提取轮廓。我们检测到HI HALO排放，在配置文件峰值上删除20模式的10型模式的显着性$12.5σ$，$13.5σ$。我们共同适合观察到的光晕质量$ m _ {\ rm v} $和标准化$ c_ {0，\ rm hi} $，用于针对重建的配置文件的HI浓度参数，并使用文献中提出的HI Halo丰度的功能形式。我们找到$ \ log_ {10} {（M _ {\ rm V}/\ text {m} _ {\ odot}）} = 16.1^{+0.1} _ { - 0.2} $ $ \ log_ {10} {（M _ {\ rm V}/\ text {m} _ {\ odot}）} = 16.5^{+0.1} _ { - 0.2} $，$ c_，$ c_ {0，$ c_ {0，\ rm hi} = 5.3^= 5.3^= 5.3^{+1.11} _aps = for tate pation。这些估计值显示了位于非常庞大的光环内部多个星系的综合贡献的检测。我们还分别考虑了13,979个中央和34,361个卫星2DF星系的子样本，并获得边缘差异，表明卫星星系是高氧化器。这项工作首次显示了直接从21厘米地图提取的配置文件上测试HI Halo含量的理论模型的可行性，并为利用即将到来的HI强度映射数据提供了未来的可能性。
We detect the neutral hydrogen (HI) radial brightness temperature profile in large-scale haloes by stacking 48,430 galaxies selected from the 2dFGRS catalogue onto a set of 21-cm intensity maps obtained with the Parkes radio telescope, spanning a total area of $\sim$1,300 $\text{deg}^2$ on the sky and covering the redshift range $0.06\lesssim z\lesssim 0.10$. Maps are obtained by removing both 10 and 20 foreground modes in the principal component analysis. We perform the stack at the map level and extract the profile from a circularly symmetrised version of the halo emission. We detect the HI halo emission with the significance $12.5σ$ for the 10-mode and $13.5σ$ for the 20-mode removed maps at the profile peak. We jointly fit for the observed halo mass $M_{\rm v}$ and the normalisation $c_{0,\rm HI}$ for the HI concentration parameter against the reconstructed profiles, using functional forms for the HI halo abundance proposed in the literature. We find $\log_{10}{(M_{\rm v}/\text{M}_{\odot})} = 16.1^{+0.1}_{-0.2}$, $c_{0,\rm HI}=3.5^{+0.7}_{-1.0}$ for the 10-mode and $\log_{10}{(M_{\rm v}/\text{M}_{\odot})} = 16.5^{+0.1}_{-0.2}$, $c_{0,\rm HI}=5.3^{+1.1}_{-1.7}$ for the 20-mode removed maps. These estimates show the detection of the integrated contribution from multiple galaxies located inside very massive haloes. We also consider sub-samples of 13,979 central and 34,361 satellite 2dF galaxies separately, and obtain marginal differences suggesting satellite galaxies are HI-richer. This work shows for the first time the feasibility of testing theoretical models for the HI halo content directly on profiles extracted from 21-cm maps and opens future possibilities for exploiting upcoming HI intensity-mapping data.
