Le 2 septembre 2016
De 10h30 à 12h00
Facundo GOMEZ
MPA Garching
During this talk I will present an overview of our recent work which aims to characterize the impact of host-satellite interactions on the observable properties of our Galaxy. Using fully cosmological simulations of the formation of the Milky Way (MW), I will start by showing how a low-mass low-velocity fly-by encounter with a pericentric distance as large as 80 kpc can excite well-defined vertical patterns on a pre-existing galactic disk. I will discuss the mechanism behind these perturbations and show how such an interaction could be enough to induce the formation of observed features such as the Monoceros Ring. Motivated by recent studies suggesting that the Large Magellanic Cloud (LMC) could be significantly more massive than previously thought, I will then explore whether the approximation of an inertial Galactocentric reference frame is still valid. I will show that previous estimates of the LMC’s orbital period and apocentric distance, derived assuming a fixed MW, are shortened if the MW is allowed to freely move in response to the gravitational pull of the LMC. Due to this interaction, the MW center of density can be strongly displaced in phase-space in a very short period of time. Such previously ignored interaction is likely to significantly affect both the orbit and phase space distribution of tidal debris from MW satellites such as the Sagittarius dwarf galaxy (Sgr). In addition, it can also affect previous estimates of the (timing) mass of the Local Group.