The impact of microlensing on the standardization of strongly lensed Type Ia supernovae
The impact of microlensing on the standardization of strongly lensed Type Ia supernovae
复制标题
DOI：
10.1093/mnras/sty1346
复制
发表时间：
2018-08-01
影响因子：
4.8
通讯作者：
Bacon, David
中科院分区：
文献类型：
--
作者：
Foxley-Marrable, Max;Collett, Thomas E.;Bacon, David
我们研究了微透镜效应对强透镜Ia型超新星（GLSNe Ia）标准化的影响。我们提出了通过一系列似是而非的强透镜宏观模型对微透镜引起的散射量的预测。我们发现在低会聚、剪切和恒星密度区域的透镜图像是可标准化的，其中微透镜散射小于或接近0.15等，与典型的SN Ia的本征色散相当。这些标准化配置对应于非对称透镜，其图像位于透镜的爱因斯坦半径之外。对称和小爱因斯坦半径透镜（小于或类似于0.5弧秒）是不可标准化的。我们将我们的模型应用于最近发现的GLSN Ia iPTF16geu，发现观测到的通量与More等人的宏观模型预测之间的巨大差异不能仅用微透镜来解释。利用Goldstein等人的模拟GLSNe Ia目录，我们预测，大型综合巡天望远镜（LSST）发现的GLSNe Ia中有22%是可标准化的，爱因斯坦半径中值为0.9弧秒，中值延迟为41 d。通过打破质量层简并，完整的LSST GLSNe Ia样本将能够以0.5%的水平检测到H-0中的系统。
We investigate the effect of microlensing on the standardization of strongly lensed Type Ia supernovae (GLSNe Ia). We present predictions for the amount of scatter induced by microlensing across a range of plausible strong lens macromodels. We find that lensed images in regions of low convergence, shear and stellar density are standardizable, where the microlensing scatter is less than or similar to 0.15 mag, comparable to the intrinsic dispersion of a typical SN Ia. These standardizable configurations correspond to asymmetric lenses with an image located far outside the Einstein radius of the lens. Symmetric and small Einstein radius lenses (less than or similar to 0.5 arcsec) are not standardizable. We apply our model to the recently discovered GLSN Ia iPTF16geu and find that the large discrepancy between the observed flux and the macromodel predictions from More et al. cannot be explained by microlensing alone. Using the mock GLSNe Ia catalogue of Goldstein et al., we predict that similar to 22 per cent of GLSNe Ia discovered by Large Synoptic Survey Telescope (LSST) will be standardizable, with a median Einstein radius of 0.9 arcsec and a median time delay of 41 d. By breaking the mass-sheet degeneracy the full LSST GLSNe Ia sample will be able to detect systematics in H-0 at the 0.5 per cent level.