Hubble Constant from LSST Strong-lens Time Delays with Microlensing Systematics
Hubble Constant from LSST Strong-lens Time Delays with Microlensing Systematics
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DOI：
10.3847/1538-4357/aaf733
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发表时间：
2018-12
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影响因子：
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通讯作者：
Kai Liao
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文献类型：
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作者：
Kai Liao
强透镜时间延迟已广泛应用于宇宙学研究中，特别是用于推断H0。即将到来的LSST将从透镜类星体的光曲线中提供数百个精确测量的时间延迟。然而，由于有限AGN吸积盘的倾斜和相干温度波动的微分放大，恒星的微透镜效应会导致发射区穿越光时间尺度上的实际时间延迟变化~天。我们首先研究了这将如何改变lst时代H0的不确定性，假设微透镜时间延迟可以很好地估计。我们分别采用1/3、1和3天作为典型的微透镜时延不确定性。H0的相对不确定度分别增大到0.47%、0.51%和0.76%，不确定度在没有微透镜的情况下影响0.45%。然后，由于我们对类星体模型和微透镜模式缺乏了解，如果在分析中忽略这种影响，我们还测试了结果的可靠性。H0的偏差将为0.12%，0.22%和0.70%，这表明1天是稳健的H0估计的截止日期。
Strong-lens time delays have been widely used in cosmological studies, especially to infer H0. The upcoming LSST will provide several hundred well-measured time delays from the light curves of lensed quasars. However, due to the inclination of the finite AGN accretion disk and the differential magnification of the coherent temperature fluctuations, the microlensing by the stars can lead to changes in the actual time delay on the light-crossing timescale of the emission region of ∼days. We first study how this would change the uncertainty of H0 in the LSST era, assuming the microlensing time delays can be well estimated. We adopt 1/3, 1, and 3 days respectively as the typical microlensing time-delay uncertainties. The relative uncertainty of H0 will be enlarged to 0.47%, 0.51%, and 0.76%, from the uncertainty without the microlensing, impact 0.45%. Then, due to our lack of understanding of the quasar models and microlensing patterns, we also test the reliability of the results if one neglects this effect in the analysis. The biases of H0 will be 0.12%, 0.22% and 0.70%, suggesting that 1 day is the cutoff for a robust H0 estimate.