论文标题
CEN A矮卫星星系的连贯运动仍然是$λ$ CDM宇宙学的挑战
The coherent motion of Cen A dwarf satellite galaxies remains a challenge for $Λ$CDM cosmology
论文作者
论文摘要
卫生馆的问题是标准$λ$ CDM宇宙学模型最严重的小规模挑战之一：银河系周围的几个矮星系，在薄的平面结构中，仙女座共同欧洲的共同欧洲。附近的椭圆星系半人马座A（CEN A）周围已经发现了类似的情况。在这封信中，我们研究了CEN的卫星系统，该系统增加了十二个新的星系，并具有VLT/MUSE观测值的视线速度。我们发现28个矮星系中有21个具有测得的速度具有连贯的运动。同样，在Illustris-TNG100宇宙学模拟中，仅在0.2％的CEN A类似物中发现了类似的扁平和连贯的移动结构，与我们是否使用其仅使用深色或流体动力运行。这些类似物不是共绕的，并且仅是出于偶然的投影而产生的，因此它们是此类模拟中短暂的结构。我们的发现表明，观察到的卫星共旋转平面是$λ$ CDM的持续挑战，这在很大程度上与Baryon物理学无关。
The plane-of-satellites problem is one of the most severe small-scale challenges for the standard $Λ$CDM cosmological model: several dwarf galaxies around the Milky Way and Andromeda co-orbit in thin, planar structures. A similar case has been identified around the nearby elliptical galaxy Centaurus A (Cen A). In this Letter, we study the satellite system of Cen A adding twelve new galaxies with line-of-sight velocities from VLT/MUSE observations. We find 21 out of 28 dwarf galaxies with measured velocities share a coherent motion. Similarly flattened and coherently moving structures are found only in 0.2% of Cen A analogs in the Illustris-TNG100 cosmological simulation, independently of whether we use its dark-matter-only or hydrodynamical run. These analogs are not co-orbiting, and arise only by chance projection, thus they are short-lived structures in such simulations. Our findings indicate that the observed co-rotating planes of satellites are a persistent challenge for $Λ$CDM, which is largely independent from baryon physics.
