论文标题
修改星系集群Abell 1644的合并情景：一种新的较差的气体结构，由弱重力镜头发现
Revising the merger scenario of the galaxy cluster Abell 1644: a new gas poor structure discovered by weak gravitational lensing
论文作者
论文摘要
Galaxy群集Abell 1644（$ \ bar {z} = 0.047 $）以其出色的类似螺旋状的X射线发射而闻名。以前，它被确定为双峰系统，包括子截面，A1644S和A1644N，每个系统都以巨大的椭圆星系为中心。在这项工作中，我们介绍了该系统的全面研究，包括新的弱透镜和动力学数据和分析以及量身定制的流体动力学模拟。镜头和星系密度图在北部显示出一个结构，在X射线图像上看不到。因此，我们将先前已知的北部光环重命名为A1644N1，而新的北极光子为A1644N2。我们的镜头数据表明，这些质量相当相似：$ m_ {200}^{\ rm n1} = 0.90 _ { - 0.85}^{+0.45} \ times10^{14} $ \ times10^{14} $ m $ _ \ odot $，而南部结构是主要的结构：$ m_ {200}^{\ rm s} = 1.90 _ { - 1.28}^{+0.89} {+0.89} \ times 10^{14} {14} $ m $ _ \ odot $。基于模拟，通过观察数据喂养，我们提出了一个方案，其中系统中出色的X射线特性是A1644S和A1644N2之间发生的$ \ sim $ \ sim $ 1.6 Gyr的结果。当前，这些系统应在达到最大分离后，应前往新的相遇。
The galaxy cluster Abell 1644 ($\bar{z}=0.047$) is known for its remarkable spiral-like X-ray emission. It was previously identified as a bimodal system, comprising the subclusters, A1644S and A1644N, each one centered on a giant elliptical galaxy. In this work, we present a comprehensive study of this system, including new weak-lensing and dynamical data and analysis plus a tailor-made hydrodynamical simulation. The lensing and galaxy density maps showed a structure in the North that could not be seen on the X-ray images. We, therefore, rename the previously known northern halo as A1644N1 and the new one as A1644N2. Our lensing data suggests that those have fairly similar masses: $M_{200}^{\rm N1}=0.90_{-0.85}^{+0.45} \times10^{14}$ and $M_{200}^{\rm N2}=0.76_{-0.75}^{+0.37} \times10^{14}$ M$_\odot$, whereas the southern structure is the main one: $M_{200}^{\rm S}=1.90_{-1.28}^{+0.89}\times 10^{14}$ M$_\odot$. Based on the simulations, fed by the observational data, we propose a scenario where the remarkable X-ray characteristics in the system are the result of a collision between A1644S and A1644N2 that happened $\sim$1.6 Gyr ago. Currently, those systems should be heading to a new encounter, after reaching their maximum separation.
