| Project AMIGA (Absorption Maps In the Gas of Andromeda) uses an unprecedented dataset of 55 sightlines obtained from two large HST COS programs to provide a unique view of the circumgalactic medium (CGM) of the Andromeda galaxy (M31). Using absorption-line spectroscopy, we map the CGM of Andromeda across a wide range of distances, spanning from 10 to 569 kpc, nearly reaching 2Rvir (Rvir=300 kpc). This extensive dataset enables us to explore, for the first time, the spatial variation of the multiphase CGM. I will present striking differences in the complexity and phase structure of Andromeda's CGM between the inner regions (50-75 kpc from the disk) and the more diffuse outer regions, revealing a significant change in the ionization levels and kinematics of the CGM gas as a function of distance from the galaxy. I will discuss our findings in the context of recent cosmological zoom simulations of ∼L* galaxies at z~0. These results provide essential insights into the physical processes governing the multiphase structure and dynamics of the CGM in a nearby massive galaxy. |
