Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies

Autor(en)
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
Abstrakt

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(en)
Institut für Astrophysik
Externe Organisation(en)
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
Band
442
Seiten
2362-2380
Anzahl der Seiten
19
ISSN
0035-8711
DOI
https://doi.org/10.1093/mnras/stu1005
Publikationsdatum
08-2014
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie, 103004 Astrophysik
Schlagwörter
ASJC Scopus Sachgebiete
Astronomy and Astrophysics, Space and Planetary Science
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/c17d69c4-d835-4aa2-b0c6-1bf4c66da454