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北美退伍军人节(Veterans Day),12 日无更新
arXiv 2008.10642astro-ph.CO
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第一个多重成像超新星II的教训:星系团MACS J1149 .5+2223的参数强透镜模型

Lessons from the first multiply imaged supernova II: A parametric strong-lensing model for the galaxy cluster MACS J1149.5+2223

Adi Zitrin

摘要:

我们提出了一个参数化的,基于网格的透镜模型的星系团MACS J1149.5+2223,集中在第一个多重成像的超新星Refsdal的属性。该模型补充了我们在一篇配套论文中描述的针对该集群的更新的光迹质量(LTM)强透镜模型,并且使用相同的管道但具有不同的参数化生成。这两个模型以相对自洽的方式共同探索不同的可能解决方案,并可用于检查系统不确定性和两个参数化之间的相关差异。我们得到合理的相似(同意在$\simeq1-3σ$,在大多数情况下)的时间延迟和放大率,相对于S1,从两种不同的方法,虽然LTM预测似乎是系统的一些图像更短/更小。最值得注意的是,爱因斯坦交叉之间的时间延迟[和95\% CI](特别是,图像S1),和SX,在最初发现十字架后大约一年出现的图像,在参数方法之间有很大的不同。(326 [300 - 359]天)和LTM方法(224 [198 - 306]天),这似乎低估了真实再现时间。这种系统性差异的原因目前尚不清楚。我们推测其可能的起源,并注意到SN Refsdal的属性的精确测量应该有助于更强烈地区分两种解决方案,从而在两种描述之间的内在形状的底层物质分布。我们还讨论了我们的结果的哈勃常数的影响。

英文摘要:

We present a parametric, grid-based lens model for the galaxy cluster MACS J1149.5+2223, concentrating on the properties of the first multiply imaged supernova Refsdal. This model complements our updated light-traces-mass (LTM) strong-lensing model for this cluster, described in a companion paper, and is generated using the same pipeline but with a different parametrization. Together these two models probe different possible solutions in a relatively self-consistent manner and can be used to examine systematic uncertainties and relevant differences between the two parameterizations. We obtain reasonably similar (agreeing to within $\simeq1-3σ$, in most cases) time delays and magnification ratios, with respect to S1, from the two different methods, although the LTM predictions seem to be systematically shorter/smaller for some of the images. Most notably, the time delay [and 95\% CI] between the Einstein cross (in particular, image S1), and SX, the image that appeared about a year after the original discovery of the cross, differs substantially between the parametric method (326 [300 -- 359] days) and the LTM method (224 [198 -- 306] days), which seems to underestimates the true reappearance time. The cause for this systematic difference is unclear at present. We speculate on its possible origin and note that a refined measurement of SN Refsdal's properties should help to more strongly discriminate between the two solutions, and thus between the two descriptions for the intrinsic shape of the underlying matter distribution. We also discuss the implications of our results for the Hubble constant.

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。

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