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arXiv 1701.01451astro-ph.GA
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斯隆数字巡天I所见的插图模拟中的Galerkin:膨胀+盘分解、方法和偏差

Galaxies in the Illustris simulation as seen by the Sloan Digital Sky Survey - I: Bulge+disc decompositions, methods, and biases

Connor Bottrell, Paul Torrey, Luc Simard, Sara L. Ellison

摘要:

我们提出了一种基于图像的方法比较流体动力学模拟中产生的星系的结构特性,以真实的星系在斯隆数字巡天。我们的工作的主要特点是引入广泛的观测现实主义,如对象拥挤,噪音和视角,模拟星系的合成图像,使它们可以公平地比较真实的星系目录。我们将我们的方法应用于$z=0$的Illustris模拟的星系无尘合成图像目录,然后用凸起+盘模型拟合以获得形态参数。在这一系列的第一篇论文中,我们详细介绍了我们的方法,量化了观测偏差,并提出了公开的bulge+disc分解目录。我们发现,我们的凸起+光盘分解在很大程度上是强大的观测偏差,影响真正的星系的分解。然而,我们确定了一个显着的人口的星系(约30\%的完整样本)在插图容易内部分割,导致系统减少通量估计的一个因素,6,较小的半光半径的一个因素的$\sim$ 2,和一般错误的膨胀总分数(B/T)=0。

英文摘要:

We present an image-based method for comparing the structural properties of galaxies produced in hydrodynamical simulations to real galaxies in the Sloan Digital Sky Survey. The key feature of our work is the introduction of extensive observational realism, such as object crowding, noise and viewing angle, to the synthetic images of simulated galaxies, so that they can be fairly compared to real galaxy catalogs. We apply our methodology to the dust-free synthetic image catalog of galaxies from the Illustris simulation at $z=0$, which are then fit with bulge+disc models to obtain morphological parameters. In this first paper in a series, we detail our methods, quantify observational biases, and present publicly available bulge+disc decomposition catalogs. We find that our bulge+disc decompositions are largely robust to the observational biases that affect decompositions of real galaxies. However, we identify a significant population of galaxies (roughly 30\% of the full sample) in Illustris that are prone to internal segmentation, leading to systematically reduced flux estimates by up to a factor of 6, smaller half-light radii by up to a factor of $\sim$ 2, and generally erroneous bulge-to-total fractions of (B/T)=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。

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