GEPI

De la conception instrumentale
à l’exploitation des observables
Accueil > Seminar on 2021.03.01 by Eduardo (...) > The response of the Milky Way to (...)

The response of the Milky Way to the Large Magellanic Cloud and the Sagittarius dwarf spheroidal

Chervin Laporte

The Milky Way disc is asymmetric about the midplane. The HI shows a warp and recent star count surveys show that the disc is rippled (both in height and streaming vertical velocity). Their respective origins are still not settled. I will show results that suggest that all these features in the disc are shaped by its two most massive satellites. I will present the first self-consistent N-body models of the MW and LMC pair in a first infall scenario designed to study the response of the disc to different mass models. I will show that a massive LMC of virial mass 2.5x10^11 Msun predicts a warp with the correct phases as the observed HI warp but no ripples. However, discrepancies remain between the models and the data, and I will discuss some possible reasons. By contrasting the response of the disc with a heavy Sgr model I will also show that no single interaction model (MW+LMC/MW+Sgr) can capture all the features seen in the disc and that one should consider the collective effect of both satellites. I will then present some revised models of Sgr interacting with the MW that I am now using to study the coupling between the LMC and Sgr on the galactic disc (Laporte et al. in prep).