论文标题
最亮星系星系的内在形状
Intrinsic shapes of Brightest Cluster Galaxies
论文作者
论文摘要
我们通过将观察到的表面亮度（SB）谱图（SB）谱图从最近发表的大型深度测量样本中引入56个最亮的星系星系的观察到的表面亮度（SB）曲线，讨论了三轴性的假设下的星系形状和视角的统计分布。我们首次通过直接测量轴比曲线来解决此问题，而不将自己限制在平均椭圆率的统计分析中。我们表明，这些对象是强烈的三轴，带有三轴性参数为0.39 $ \ leq t \ leq $ 0.72，平均轴比为$ <p（r）> = $ 0.84和$ <q（r）> = $ 0.68，在中央区域中更具球形，但在大型radii中更扁平。郊区的测得的形状与来自Illustristng和磁模拟的模拟大型星系和它们的暗物质光环的形状非常吻合，可能会探测暗物质的性质。相比之下，两个模拟都无法再现观测到的BCG的内部区域，从而产生了太平坦的物体。
We discuss the statistical distribution of galaxy shapes and viewing angles under the assumption of triaxiality by deprojecting observed Surface Brightness (SB) profiles of 56 Brightest Cluster Galaxies coming from a recently published large deep-photometry sample. For the first time, we address this issue by directly measuring axis ratio profiles without limiting ourselves to a statistical analysis of average ellipticities. We show that these objects are strongly triaxial, with triaxiality parameters 0.39 $ \leq T \leq $ 0.72, have on average axis ratios $< p(r) > = $ 0.84 and $< q(r) > =$ 0.68, and are more spherical in the central regions but flatten out at large radii. Measured shapes in the outskirts agree well with the shapes found for simulated massive galaxies and their dark matter halos from both the IllustrisTNG and the Magneticum simulations, possibly probing the nature of dark matter. In contrast, both simulations fail to reproduce the observed inner regions of BCGs, producing too flattened objects.
