The coherent motion of Cen A dwarf satellite galaxies remains a challenge for $\Lambda$CDM cosmology
In: Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2021, 645, pp.L5. ⟨10.1051/0004-6361/202039973⟩; (2020-12-15)
Online
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Zugriff:
The plane-of-satellites problem is one of the most severe small-scale challenges for the standard $\Lambda$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 $\Lambda$CDM, which is largely independent from baryon physics.
Comment: 7 pages, 4 figures, 1 table, published in Astronomy & Astrophysics Letters
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The coherent motion of Cen A dwarf satellite galaxies remains a challenge for $\Lambda$CDM cosmology
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Autor/in / Beteiligte Person: | Lelli, Federico ; Libeskind, Noam I. ; Rejkuba, Marina ; Müller, Oliver ; Fahrion, K. ; Pawlowski, Marcel S. ; Hilker, Michael ; Kanehisa, Jamie ; Jerjen, Helmut ; Centre Hospitalier Universitaire Vaudois [Lausanne] (CHUV) ; Institut de Physique des 2 Infinis de Lyon (IP2I Lyon) ; Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS) |
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Quelle: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2021, 645, pp.L5. ⟨10.1051/0004-6361/202039973⟩; (2020-12-15) |
Veröffentlichung: | 2020 |
Medientyp: | unknown |
ISSN: | 0004-6361 (print) |
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