论文标题
HI 21cm中间吸收剂作为潜在宇宙加速探针的统计分布
Statistical distribution of HI 21cm intervening absorbers as potential cosmic acceleration probes
论文作者
论文摘要
阻尼Lyman-$α$吸收器（DLA）或HI 21厘米吸收剂（H21A）是通过Sandage-loeb（SL）效应的型号与模型独立地测量光谱速度（$ v_ \ mathrm {s} $）的加速度的重要探针。由于DLA和背景无线电源短缺（BRS）的限制，可检测到的DLA量在以前的大部分工作中都模棱两可。在将比例因子的加速度（$ \ ddot {a} $）与光谱速度的一阶时间衍生物（$ \ dot {v} _ \ mathrm {s} $）不同之后，我们对本文中潜在DLA的数量进行了统计研究。使用内核密度估计（KDE）来描述BRS的一般红移分布，观察到的DLA和具有不同限制的DLA检测率（1.4GHz通量，HI柱密度和自旋温度），我们提供了三个成分的多高斯表达式，可通过bootstrap和bootstrap tefterions tectutions to bootsions bootsiont the bootsions hH 21 $σ$ nivestrap，bootsions bootsions to bootsiont teption to boots tote to boots the boots the boots hH 21 n21 HI吸收盲目调查中的H21A的数量预测，对快速，ASKAP和SKA1-MID的数量预测。在我们最乐观的条件下（$ f_ \ mathrm {1.4Ghz} $> 10mjy，$ n_ \ mathrm {hi}> 2 \ times10^{20} \ Mathrm {cm^{ - 2}} $ H21as。
Damped Lyman-$α$ Absorber (DLA), or HI 21cm Absorber (H21A), is an important probe to model-independently measure the acceleration of spectroscopic velocity ($v_\mathrm{S}$) via the Sandage-Loeb (SL) effect. Confined by the shortage of DLAs and Background Radio Sources (BRSs) with adequate information, the detectable amount of DLAs is ambiguous in the bulk of previous work. After differing the acceleration of scale factor ($\ddot{a}$) from the first order time derivative of spectroscopic velocity ($\dot{v}_\mathrm{S}$), we make a statistical investigation of the amount of potential DLAs in the most of this paper. Using Kernel Density Estimation (KDE) to depict general redshift distributions of BRSs, observed DLAs and a DLA detection rate with different limitations (1.4GHz flux, HI column density and spin temperature), we provide fitted multi-Gaussian expressions of the three components and their 1$σ$ regions by bootstrap, with a proportional constant of H21As in detected DLAs, leading to the measurable number predictions of H21As for FAST, ASKAP and SKA1-Mid in HI absorption blind survey. In our most optimistic condition ($F_\mathrm{1.4GHz}$>10mJy, $N_\mathrm{HI}>2\times10^{20}\mathrm{cm^{-2}}$ and $T_\mathrm{S}$>500K), the FAST, AKSAP and SKA1-Mid would probe about 80, 500 and 600 H21As respectively.
