Reconstructing the projected gravitational potential of Abell 1689 from X-ray measurements
Reconstructing the projected gravitational potential of Abell 1689 from X-ray measurements
复制标题
根据 X 射线测量重建 Abell 1689 的预计引力势
DOI：
10.1051/0004-6361/201323242
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发表时间：
2015
影响因子：
6.5
通讯作者：
M. Bartelmann
中科院分区：
文献类型：
--
作者：
C. Tchernin;C. L. Majer;S. Meyer;E. Sarli;D. Eckert;M. Bartelmann
背景星系团可以用作宇宙学探测器，但为此，需要彻底了解它们。以一致的方式组合所有星系团的可观测性将有助于我们了解它们的全球性质和内部结构。目的我们证明了星系团的投射引力势可以直接从X射线观测中重建的概念。我们还表明，这种联合分析可以用来局部检验星系团平衡假设的有效性。方法我们使用了一种新开发的基于Richardson-Lucy反投影的重建方法，该方法可以直接根据X射线观测重建星系团的投影引力势。我们将这个算法应用于研究得很好的星系团Abell 1689，并将由X射线观测数据重建的引力势与由引力透镜测量得到的引力势进行了比较。我们还将Richardson-Lucy反投影算法得到的X射线反投影分布与更传统的洋葱剥离技术得到的结果进行了比较。结果在球对称和流体静力平衡的假设下，从引力透镜和X射线发射中恢复的势在500kpc以上非常吻合。由于Richardson-Lucy反投影算法允许独立地对每条视线进行反投影，这一结果可能表明在星系团的中心区域非引力效应和/或非球面性很强。结论我们证明了基于Richardson-Lucy反投影算法的势重建方法的稳健性，并表明引力透镜和X射线发射导致了一致的引力势。我们的结果说明了在一个单一的、非参数的、可用于局部约束气体物理状态的一致团簇势的联合重建中组合星系团的可观察性的能力。
ContextGalaxy clusters can be used as cosmological probes, but to this end, they need to be thoroughly understood. Combining all cluster observables in a consistent way will help us to understand their global properties and their internal structure.AimsWe provide proof of the concept that the projected gravitational potential of galaxy clusters can directly be reconstructed from X-ray observations. We also show that this joint analysis can be used to locally test the validity of the equilibrium assumptions in galaxy clusters.MethodsWe used a newly developed reconstruction method, based on Richardson-Lucy deprojection, that allows reconstructing projected gravitational potentials of galaxy clusters directly from X-ray observations. We applied this algorithm to the well-studied cluster Abell 1689 and compared the gravitational potential reconstructed from X-ray observables to the potential obtained from gravitational lensing measurements. We also compared the X-ray deprojected profiles obtained by the Richardson-Lucy deprojection algorithm with the findings from the more conventional onion-peeling technique.ResultsAssuming spherical symmetry and hydrostatic equilibrium, the potentials recovered from gravitational lensing and from X-ray emission agree very well beyond 500 kpc. Owing to the fact that the Richardson-Lucy deprojection algorithm allows deprojecting each line of sight independently, this result may indicate that non-gravitational effects and/or asphericity are strong in the central regions of the clusters.ConclusionsWe demonstrate the robustness of the potential reconstruction method based on the Richardson-Lucy deprojection algorithm and show that gravitational lensing and X-ray emission lead to consistent gravitational potentials. Our results illustrate the power of combining galaxy-cluster observables in a single, non-parametric, joint reconstruction of consistent cluster potentials that can be used to locally constrain the physical state of the gas.