Phase-space Correlations of Satellite Galaxy Systems and Challenges to ?CDM Cosmology
Abstract
Driven by the increasingly complete observational knowledge of systems of satel- lite galaxies, mutual spatial alignments and relations in velocities among satellites belonging to a common host have become a productive field of research. The Planes of Satellite Galax- ies issue is maybe the best-known type of such phase-space correlations, with an ongoing, controversial debate on how much of a challenge it poses for the $\Lambda$CDM model of cosmology. With the fast expansion of proper motion measurements in recent years, largely driven by the Gaia mission, other peculiar phase-space correlations have been uncovered among the satellites of the Milky Way. At the same time, more complete observational samples of satellite galaxies around more distant hosts now enable us to expand the study of such cor- relations to the Andromeda galaxy and beyond. This contribution briefly reviews the highly active field of phase-space correlations among satellite galaxy systems, mainly summarizing recent results concerning observed satellite structures and what formation scenarios have been suggested for these peculiar arrangements.
- Publication:
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Publications de l'Observatoire Astronomique de Beograd
- Pub Date:
- December 2024
- DOI:
- Bibcode:
- 2024POBeo.104...59P