2018/01/31 by Oliver Müller, Marcel S. Pawlowski, Helmut Jerjen +1 · 5 citations
Physics and Astronomy · #Andromeda Galaxy #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Centaurus A #Cold dark matter #Cosmology #Cosmology and Gravitation Theories #Dark matter #Dwarf galaxy problem #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Galaxy group #Milky Way #Physics #Radio galaxy #Satellite galaxy #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1126/science.aao1858
Published in the first Feb 2018 issue of Science (Müller et al., Science 359, 534, 2018). This preprint corresponds to the accepted and language edited version of the manuscript. 32 pages, 5 figures
arxiv created 2018/01/31 · openalex publication_date 2018/02/01 · arxiv updated 2018/02/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The Milky Way and Andromeda galaxies are each surrounded by a thin plane of satellite dwarf galaxies that may be corotating. Cosmological simulations predict that most satellite galaxy systems are close to isotropic with random motions, so those two well-studied systems are often interpreted as rare statistical outliers. We test this assumption using the kinematics of satellite galaxies around the Centaurus A galaxy. Our statistical analysis reveals evidence for corotation in a narrow plane: Of the 16 Centaurus A satellites with kinematic data, 14 follow a coherent velocity pattern aligned with the long axis of their spatial distribution. In standard cosmological simulations, <0.5% of Centaurus A-like systems show such behavior. Corotating satellite systems may be common in the universe, challenging small-scale structure formation in the prevailing cosmological paradigm.