Presentation on theme: "From the Milky Way to Andromeda: A PAndAS View of Galactic Halos Brendan McMonigal Supervisor - Geraint F. Lewis Sydney Institute for Astronomy School."— Presentation transcript:
From the Milky Way to Andromeda: A PAndAS View of Galactic Halos Brendan McMonigal Supervisor - Geraint F. Lewis Sydney Institute for Astronomy School of Physics, The University of Sydney Original image: Stephen Rahn (Flikr)
Outline A PAndAS Introduction Mapping the contamination The Smooth Halo of M31 A new MW Stream
Canada-France-Hawaii Telescope CFHT – 3.6m on Hawaii PAndAS (Pan-Andromeda Archaeological Survey) MegaCam (~1 degree FOV)
Andromeda & Triangulum (M31 & M33) M31 is a grand design spiral very similar to the MW, located at 780kpc. M33 has a mass ~1/10 th that of the MW, located at a distance of 860kpc. Separated on the sky by ~15 degrees on the sky (physical separation of 230kpc) and M33 may be a bound satellite of M31, although it appears to be very undisturbed.
Koposov et al (2012) SDSS-III Substructure in the Milky Way
Martin et al. (2014) Substructure in the Milky Way
Take home points… PAndAS: We now have the most comprehensive view of a galaxy halo out to 150kpc (as well as to 50kpc in M33) Substructure: We see extensive substructure, consisting of streams and clumps, both in Andromeda and the MW. Dwarf Population: We’ve uncovered a large populations of dwarf galaxies, but still not as many as expected from cosmological predictions (modulo gas physics). Still to come: Globular Clusters (Nick), 3D structure (Anthony)