arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2103.08609astro-ph.COastro-ph.GA
收藏

改进的时延透镜模型和瞬态源的$H_0$推断

Improved time-delay lens modelling and $H_0$ inference with transient sources

Xuheng Ding, Kai Liao, Simon Birrer, Anowar J. Shajib, Tommaso Treu, Lilan Yang

备注：
9 pages, 4 figures, MNRAS accepted, comments welcome
发表信息：
MNRAS, (2021), 504, 5621
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

除了强透镜类星体外，超新星、伽马射线暴、快速射电暴和引力波等强透镜爆炸瞬变现象也是确定哈勃常数（$H_0$）的重要工具。在这项工作中，我们表明，点源的瞬态性质提供了一个优势，类星体：透镜的宿主星系可以观察到之前或之后的瞬态的外观。因此，透镜模型可以从没有来自亮点源的污染的图像导出。我们通过比较从具有和不具有点源的相同透镜获得的透镜模型的精度来量化这种优势。基于哈勃太空望远镜（HST）宽视场相机3（WFC 3）的观测，使用相同的透镜参数集，我们模拟了48个类星体透镜系统的真实模拟数据集（即，在星系中心增加活动星系核）和48个星系-星系透镜系统（假设瞬变源不可见，但时间延迟和图像位置已经或将要测量）。然后，我们对图像进行建模，并比较晶状体模型参数和$H_0$的推断。我们发现，透镜模型的精度（在偏转器质量斜率方面）是更好的一个因素为4.1的样品没有透镜点源，导致$H_0$精度增加了2.9倍。在没有瞬态点源的情况下观察透镜系统的机会为时滞宇宙学提供了比透镜类星体更大的优势。它有助于确定主偏转器的高信噪比恒星运动学，从而确定其质量密度分布，这反过来又在打破质量片简并和约束$H_0$中起着关键作用。

英文摘要：

Strongly lensed explosive transients such as supernovae, gamma-ray bursts, fast radio bursts, and gravitational waves are very promising tools to determine the Hubble constant ($H_0$) in the near future in addition to strongly lensed quasars. In this work, we show that the transient nature of the point source provides an advantage over quasars: the lensed host galaxy can be observed before or after the transient's appearance. Therefore, the lens model can be derived from images free of contamination from bright point sources. We quantify this advantage by comparing the precision of a lens model obtained from the same lenses with and without point sources. Based on Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) observations with the same sets of lensing parameters, we simulate realistic mock datasets of 48 quasar lensing systems (i.e., adding AGN in the galaxy center) and 48 galaxy-galaxy lensing systems (assuming the transient source is not visible but the time delay and image positions have been or will be measured). We then model the images and compare the inferences of the lens model parameters and $H_0$. We find that the precision of the lens models (in terms of the deflector mass slope) is better by a factor of 4.1 for the sample without lensed point sources, resulting in an increase of $H_0$ precision by a factor of 2.9. The opportunity to observe the lens systems without the transient point sources provides an additional advantage for time-delay cosmography over lensed quasars. It facilitates the determination of higher signal-to-noise stellar kinematics of the main deflector, and thus its mass density profile, which in turn plays a key role in breaking the mass-sheet degeneracy and constraining $H_0$.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑