Deprojection of Rich Cluster Images
Deprojection of Rich Cluster Images
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DOI：
10.1086/311421
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发表时间：
1998-04
期刊：
影响因子：
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通讯作者：
S. Zaroubi;G. Squires;Y. Hoffman;Y. Hoffman;J. Silk
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文献类型：
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作者：
S. Zaroubi;G. Squires;Y. Hoffman;Y. Hoffman;J. Silk
我们考虑一种通用的方法，通过对二维图像进行反投影来重建投影物体的三维结构，假设轴对称。该方法包括将傅里叶切片定理应用于一般情况，其中对称轴不一定垂直于视线，并且基于图像傅里叶变换到所谓的无知锥的外推。该方法专为 X 射线、Sunyaev-Zeldovich (SZ) 和丰富星系团的引力透镜图的反投影而设计。对于哈勃常数 H0 和倾角的已知值，投影的质量取决于无知锥体中外推法的精确程度。在对称轴垂直于视线且图像无噪声的情况下，反投影是准确的。给定 H0 的假设值，可以通过匹配给定簇的两个不同图像（例如 SZ 和 X 射线图）的反投影结构来找到倾斜角。然而，该解决方案由于其对假设 H0 的依赖性而退化，并且还需要给定簇的第三个独立图像来确定 H0。将反投影算法应用于即将推出的 SZ、X 射线和弱透镜团簇投影质量图像将有助于确定丰富团簇的结构和 H0 值，并对团簇内气体的物理性质及其与总质量分布的关系施加约束。该方法使用一个简单的星团暗物质和气体分布分析模型进行了演示，并被证明可以提供星团三维结构的稳定且独特的重建。
We consider a general method of deprojecting two-dimensional images to reconstruct the three-dimensional structure of the projected object, assuming axial symmetry. The method consists of the application of the Fourier slice theorem to the general case in which the axis of symmetry is not necessarily perpendicular to the line of sight and is based on an extrapolation of the image Fourier transform into the so-called cone of ignorance. The method is specifically designed for the deprojection of X-ray, Sunyaev-Zeldovich (SZ), and gravitational lensing maps of rich clusters of galaxies. For known values of the Hubble constant H0 and inclination angle, the quality of the projection depends on how exact the extrapolation in the cone of ignorance is. In the case in which the axis of symmetry is perpendicular to the line of sight and the image is noise-free, the deprojection is exact. Given an assumed value of H0, the inclination angle can be found by matching the deprojected structure out of two different images of a given cluster, e.g., SZ and X-ray maps. However, this solution is degenerate with respect to its dependence on the assumed H0, and a third independent image of the given cluster is needed to determine H0 as well. The application of the deprojection algorithm to upcoming SZ, X-ray, and weak lensing projected mass images of clusters will serve to determine the structure of rich clusters and the value of H0 and to place constraints on the physics of the intracluster gas and its relation to the total mass distribution. The method is demonstrated using a simple analytic model for cluster dark matter and gas distributions and is shown to provide a stable and unique reconstruction of the cluster three-dimensional structure.