The coherent motion of Cen A dwarf satellite galaxies remains a challenge for ΛCDM cosmology
The coherent motion of Cen A dwarf satellite galaxies remains a challenge for ΛCDM cosmology
复制标题
Cen A矮卫星星系的相干运动仍然是ΛCDM宇宙学的挑战
DOI：
10.1051/0004-6361/202039973
复制
发表时间：
2020
影响因子：
6.5
通讯作者：
H. Jerjen
中科院分区：
文献类型：
--
作者：
O. Muller;M. Pawlowski;F. Lelli;K. Fahrion;M. Rejkuba;M. Hilker;Jamie Kanehisa;N. Libeskind;H. Jerjen
卫星平面问题是标准Λ冷暗物质（ΛCDM）宇宙学模型最严重的小尺度挑战之一：银河系和仙女座周围的几个矮星系以薄的平面结构共轨。在附近的椭圆星系半人马座A（Cen A）周围也发现了类似的情况。在这封信中，我们研究了Cen A的卫星系统，从VLT/MUSE观测中增加了12个新的星系。我们发现，21的28个矮星系的速度测量共享一个相干运动。同样，在Illustris-TNG 100宇宙学模拟中，只有0.2%的Cen A类似物中发现了扁平和相干移动的结构，这与我们是否使用其仅暗物质或流体动力学运行无关。这些类似物不是共轨的，它们只是通过偶然的投射而出现，因此它们在这种模拟中是短暂的结构。我们的研究结果表明，观测到的卫星同向旋转平面是对ΛCDM的持续挑战，这在很大程度上独立于重子物理。
The plane-of-satellites problem is one of the most severe small-scale challenges for the standard Λ cold dark matter (ΛCDM) 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 that 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 they 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 ΛCDM, which is largely independent from baryon physics.
影响因子：
4.8
作者：
J. Samuel;A. Wetzel;S. Chapman;E. Tollerud;P. Hopkins;M. Boylan-Kolchin;J. Bailin;C. Faucher-Giguère
通讯作者：
J. Samuel;A. Wetzel;S. Chapman;E. Tollerud;P. Hopkins;M. Boylan-Kolchin;J. Bailin;C. Faucher-Giguère