论文标题
四倍体成像的超新星IPTF16GEU中的镜头星系的两个组件质量模型
Two-component mass models of the lensing galaxy in the quadruply imaged supernova iPTF16geu
论文作者
论文摘要
在4年前观察到了第一个解决的，乘成像的超新星IPATF16GEU，即首先设想了此类系统后的五十年。由于来源的独特特性，这些系统对研究星系结构和宇宙学参数具有很大的希望。但是，这个第一个例子为建模者提供了一些难题。可以预期，要解释图像通量恒星对微透明的贡献，但是要适应微透明的大小，椭圆形能量镜头镜头模型的密度斜率必须非常浅，$ρ_{2d} \ propto r^{ - 0.7} $。此外，质量中心必须从观察到的光中置换约0.1 kpc，并且光分布的位置角度与质量的位置分布不一致约40度。在本文中，我们提出了解决前两个问题的质量模型，并提出了第三个问题的解决方案。我们的质量模型由观察到局部椭圆形的观察以及对星系尺度镜头的一些分析，包括两个偏移量（Baryonic）质量成分。所得的质量分布具有单个质心，但偏斜，并且具有不纯粹椭圆形且与半径不相似的同学轮廓。对于我们的许多模型，微透镜的要求是适度的，而扩展的超新星宿主星系形成的环类似于观察到的一个。
The first resolved, multiply imaged supernova Type Ia, iPTF16geu, was observed 4 years ago, five decades after such systems were first envisioned. Because of the unique properties of the source, these systems hold a lot of promise for the study of galaxy structure and cosmological parameters. However, this very first example presented modelers with a few puzzles. It was expected that to explain image fluxes a contribution from microlensing by stars would be required, but to accommodate the magnitude of microlensing, the density slope of the elliptical power law lens model had to be quite shallow, $ρ_{2D} \propto r^{-0.7}$. Furthermore, the center of mass had to be displaced from that of observed light by ~0.1 kpc, and the position angle of light distribution was misaligned with that of mass by ~40 degrees. In this paper we present mass models that resolve the first two problems, and suggest a resolution of the third. Motivated by observations of local ellipticals, and some recent analysis of galaxy-scale lenses, our mass models consist of two offset (baryonic) mass components. The resulting mass distributions have a single centroid, but are lopsided, and have isodensity contours that are not purely elliptical and not self-similar with radius. For many of our models the microlensing requirements are modest, and the ring formed by the extended supernova host galaxy resembles the observed one.
