Understanding planes of satellites

R. DOMINGUEZ-TENREIRO; M. GOMEZ-FLECHOSO; S. PEDROSA; H. ARTAL; C. BROOK; BIGNONE, L.; I. SANTOS-SANTOS; A. SERNA; P. TISSERA

Salamanca

Congreso; Highlights on Spanish Astrophysics X, Proceedings of the XIII Scientific Meeting of the Spanish Astronomical Society; 2018

Planes of satellites are observed in the Milky Way and Andromeda, and recent observationsclaim their presence as well in other nearby galactic systems. Moreover, recent propermotion data of MW satellites allege an important fraction of satellites are co-orbiting withinthe plane they define. However, the quality and degree of co-orbitation of the planes ofsatellites reported so far from simulations within a ΛCDM context have been insufficientto explain the observational data. In order to further understand the origin of planes ofsatellites we have carried out a detailed study of planes of satellites in zoom-in cosmologicalhydro-simulations of disc galaxies, focusing on plane-finding methods and plane qualityanalyses. We report on a method to identify kinematically-coherent satellites based ontheir orbital angular momentum vectors. We find a group of co-orbiting satellites in thePDEVA-5004 simulation that forms a persistent planar structure across cosmic time, withcharacteristics compatible with those of the observed planes in the MW and M31.