Magellanic satellites in ?CDM cosmological hydrodynamical simulations of the Local Group

We use the APOSTLE $\Lambda$CDM cosmological hydrodynamical simulations of Local Group to study recent accretion massive satellites into halo Milky Way (MW)-sized galaxies. These systems are selected be close analogues Large Magellanic Cloud (LMC), most satellite MW. The allow us address, in a context, impact Clouds on MW, including contribution MW population, and constraints placed Galactic potential by motion LMC. show that LMC-like twice more common around Group-like primaries than isolated halos similar mass; these come from large turnaround radii highly eccentric orbits whose velocities at first pericentre comparable with primary's escape velocity. This implies $V_{\rm esc}^{\rm MW} (50 $ kpc$)\sim 365$ km/s, strong constraint models. LMC contribute about 2 $M_*>10^5\, M_\odot$, having thus only mild luminous population their hosts. At pericentre, LMC-associated position velocity, distributed along LMC's orbital plane. Their angular momenta roughly align LMC's, but, interestingly, they may appear "counter-rotate" some cases. criteria refine earlier estimates association satellites: SMC, Hydrus1, Car3, Hor1, Tuc4, Ret2 Phoenix2 compatible all criteria. Carina, Grus2, Hor2 Fornax less probable associates given relative