论文标题
TDCOSMO IV：分层时间延迟宇宙学 - 哈勃常数和星系密度曲线的联合推断
TDCOSMO IV: Hierarchical time-delay cosmography -- joint inference of the Hubble constant and galaxy density profiles
论文作者
论文摘要
通过重力镜头时间推断的H0licow协作延迟了哈勃常数$ h_0 = 73.3^{+1.7} _ { - 1.8} $ km s $ s $ s $^{ - 1} {\ rm mpc}^{ - 1}^{ - 1} $，描述偏差的质量质量密度pifiles take defloctor spector take a targe a is andart power power power halos Plus Sarth Plus Sarth Plus Sarts Plus Sarth Plus Sarth Plus Sarth Plus Sarth Plus Sarth Plus Sarth Plus Sarth Plus Sarth Plus Sarth。使镜头观察物保持不变的质量表变换（MST）被认为是$ H_0 $中残留不确定性的主要来源。我们用柔性质量模型量化了MST的任何潜在效果，这些模型与H0最大化。我们的计算基于一种新的分层方法，其中MST仅受到恒星运动学的约束。该方法在流体动力学模拟镜片上进行了验证。我们将方法应用于7个镜头的TDCOSMO样品（从H0licow产生的6个），并测量$ H_0 = 74.5^{+5.6} _ { - 6.1} $ s $ s $ s $^{ - 1} {\ rm mpc}^{ - 1} $。为了进一步限制偏转器质量轮廓，我们为SLAC样品中的33个强重力透镜添加了成像和光谱。对于9个SLAC镜头，我们使用已解决的运动学来限制恒星各向异性。根据TDCOSMO+SLAC样本的联合分析，我们测量$ H_0 = 67.4^{+4.1} _ { - 3.2} $ km s $ s $^{ - 1} {\ rm mpc}^{ - 1} $，假设是TDCOSMO和SLACS GALAXIS的drakn ancepend ancepends ancepents callaxs callaxs and ancepends ancepends callaxs and ancepend callaxs ancepend ancepend callaxs and ancepends ancependsectn。盲h0licow，仅tdcosmo-filly和tdcosmo+SLACS分析是相互统计一致的。 TDCOSMO+SLACS分析比仅H0licow或TDCOSMO的质量略有较浅。尽管我们的新分析在统计学上并未使H0licow的质量概况假设无效，因此依赖于这些假设的$ H_0 $测量值，但它表明了了解椭圆星系的质量密度谱的重要性。在本文中得出的$ H_0 $的不确定性可以通过质量概况的形式或其他数据的物理或观察先验来减少，或者通过其他数据主要是透镜星系的空间解析的运动学。
The H0LiCOW collaboration inferred via gravitational lensing time delays a Hubble constant $H_0=73.3^{+1.7}_{-1.8}$ km s$^{-1}{\rm Mpc}^{-1}$, describing deflector mass density profiles by either a power-law or stars plus standard dark matter halos. The mass-sheet transform (MST) that leaves the lensing observables unchanged is considered the dominant source of residual uncertainty in $H_0$. We quantify any potential effect of the MST with flexible mass models that are maximally degenerate with H0. Our calculation is based on a new hierarchical approach in which the MST is only constrained by stellar kinematics. The approach is validated on hydrodynamically simulated lenses. We apply the method to the TDCOSMO sample of 7 lenses (6 from H0LiCOW) and measure $H_0=74.5^{+5.6}_{-6.1}$ km s$^{-1}{\rm Mpc}^{-1}$. In order to further constrain the deflector mass profiles, we then add imaging and spectroscopy for 33 strong gravitational lenses from the SLACS sample. For 9 of the SLAC lenses we use resolved kinematics to constrain the stellar anisotropy. From the joint analysis of the TDCOSMO+SLACS sample, we measure $H_0=67.4^{+4.1}_{-3.2}$ km s$^{-1}{\rm Mpc}^{-1}$, assuming that the TDCOSMO and SLACS galaxies are drawn from the same parent population. The blind H0LiCOW, TDCOSMO-only and TDCOSMO+SLACS analyses are in mutual statistical agreement. The TDCOSMO+SLACS analysis prefers marginally shallower mass profiles than H0LiCOW or TDCOSMO-only. While our new analysis does not statistically invalidate the mass profile assumptions by H0LiCOW, and thus their $H_0$ measurement relying on those, it demonstrates the importance of understanding the mass density profile of elliptical galaxies. The uncertainties on $H_0$ derived in this paper can be reduced by physical or observational priors on the form of the mass profile, or by additional data, chiefly spatially resolved kinematics of lens galaxies.
