Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies
- Author(s)
- Marcel S. Pawlowski, Benoit Famaey, Helmut Jerjen, Gerhard Hensler, David J. Merritt, Pavel Kroupa, Joerg Dabringhausen, Fabian Lüghausen, Duncan A. Forbes, Francois Hammer, Mathieu Puech, Sylvain Fouquet, H. Flores, Yanbin Yang
- Abstract
Both major galaxies in the Local Group host planar distributions of co-orbiting satellite galaxies, the Vast Polar Structure (VPOS) of the MilkyWay and the Great Plane of Andromeda (GPoA). The Λ cold dark matter (ΛCDM) cosmological model did not predict these features. However, according to three recent studies the properties of the GPoA and the flattening of the VPOS are common features among subhalo based ΛCDM satellite systems, and the GPoA can be naturally explained by satellites being acquired along cold gas streams.We point out some methodological issues in these studies: either the selection of model satellites is different from that of the observed ones, or an incomplete set of observational constraints has been considered, or the observed satellite distribution is inconsistent with basic assumptions. Once these issues have been addressed, the conclusions are different: features like the VPOS and GPoA are very rare (each with probability ≲10
-3, and combined probability <10
-5) if satellites are selected from a ΛCDM simulation combined with semi-analytic modelling, and accretion along cold streams is no natural explanation of the GPoA. The origin of planar dwarf galaxy structures remains unexplained in the standard paradigm of galaxy formation.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Australian National University, Unknown External Organisation Unbekannt/undefiniert, Université Paris VII - Paris-Diderot, Case Western Reserve University, Université de Strasbourg, Rochester Institute of Technology, Universidad de Concepción, Swinburne University of Technology, Rheinische Friedrich-Wilhelms-Universität Bonn
- Journal
- Monthly Notices of the Royal Astronomical Society
- Volume
- 442
- Pages
- 2362-2380
- No. of pages
- 19
- ISSN
- 0035-8711
- DOI
- https://doi.org/10.1093/mnras/stu1005
- Publication date
- 08-2014
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/c17d69c4-d835-4aa2-b0c6-1bf4c66da454