论文标题
使用强度成像的类星体中强透镜时间延迟的累积分布的累积分布的$ H_0 $的4％测量值
A 4% measurement of $H_0$ using the cumulative distribution of strong-lensing time delays in doubly-imaged quasars
论文作者
论文摘要
在大规模调查的出现中，为了精确衡量$ H_0 $，对强大的镜头及其对应时间进行单独建模将变得昂贵且非常复杂。一种免费的方法是研究时间表的累积分布函数（CDF），其中将全球镜头人口与$ H_0 $一起建模。在本文中，我们使用一套水力学模拟来估计来自双重成像的类星体的时间表的CDF，以实现镜片的现实分布。我们发现，CDF表现出大量的晕圈差异，由密度剖面内斜率和总质量调节，总质量在$ 5 $ $ KPC之内。以拟合数据的目的，我们使用主组件分析来压缩CDF，并拟合由三个物理特征组成的高斯过程回归器：镜头的红移，$ z _ {\ rm l} $;光环的电力法指数，$α$和质量$ kpc $ 5 $，以及四个宇宙学特征。假设有一个平坦的宇宙，我们将模型适合27个双成像的类星体找到$ H_0 = 71 = 71^{+2} _ { - 3} $ km/s/s/mpc，$ z _ {\ rm lm l} = 0.36 = 0.36 _ { - 0.09}} $α= -1.8 _ { - 0.1}^{+0.1} $，$ \ log（m（<5 $ kpc $）/m _ \ odot）= 11.1 _ { - 0.1}^{+0.1}^{+0.1} $，; $ω_ {\rmλ} = 0.7 _ { - 0.04}^{+0.04} $。我们将$ z {\ rm lm l} $和$ \ log（m（<5 $ kpc $）/m_ \ odot）$的估计值与数据进行比较，并发现在数据的敏感性中，它们没有系统地偏见。我们生成模拟CDF，并发现Vera Rubin天文台（VRO）可以测量$σ/H_0 $至$ <3 \％$，受模型精度的限制。如果我们要充分利用VRO，则需要模拟以探索所有可能的系统学的各种反馈模型来对较大比例的晶状体种群进行采样。
In the advent of large scale surveys, individually modelling strong-gravitational lenses and their counterpart time-delays in order to precisely measure $H_0$ will become computationally expensive, and highly complex. A complimentary approach is to study the cumulative distribution function (CDF) of time-delays where the global population of lenses is modelled along with $H_0$. In this paper we use a suite of hydro-dynamical simulations to estimate the CDF of time-delays from doubly-imaged quasars for a realistic distribution of lenses. We find that the CDFs exhibit large amounts of halo-halo variance, regulated by the density profile inner slope and the total mass within $5$kpc. With the objective of fitting to data, we compress the CDFs using Principal Component Analysis and fit a Gaussian Processes Regressor consisting of three physical features: the redshift of the lens, $z_{\rm L}$; the power law index of the halo, $α$, and the mass within $5$kpc, plus four cosmological features. Assuming a flat Universe, we fit our model to 27 doubly-imaged quasars finding $H_0=71^{+2}_{-3}$km/s/Mpc, $z_{\rm L} = 0.36_{-0.09}^{+0.2} $, $α=-1.8_{-0.1}^{+0.1}$, $\log(M(<5$kpc$)/M_\odot)=11.1_{-0.1}^{+0.1} $, $Ω_{\rm M} = 0.3_{-0.04}^{+0.04} $ and $Ω_{\rm Λ}=0.7_{-0.04}^{+0.04}$. We compare our estimates of $z_{\rm L}$ and $\log(M(<5$kpc$)/M_\odot)$ to the data and find that within the sensitivity of the data, they are not systematically biased. We generate mock CDFs and find with that the Vera Rubin Observatory (VRO) could measure $σ/H_0$ to $<3\%$, limited by the precision of the model. If we are to exploit fully VRO, we require simulations that sample a larger proportion of the lens population, with a variety of feedback models, exploring all possible systematics.
