Raja Guha Thakurta - Galaxies Inside and Out: the Resolved Stellar Populations of the Milky Way etc.

WSU Physics Colloquium: 12 October 2023
Raja Guha Thakurta: Galaxies Inside and Out - the Resolved Stellar Populations of the Milky Way, Andromeda, and Triangulum galaxies.
I will present results from our group's recent/ongoing single epoch and time domain spectroscopic, photometric, and astrometric studies of the resolved stellar populations of our Galaxy and two of its large galactic companions in the Local Group, Andromeda (M31) and Triangulum (M33). We have used a combination of Keck/DEIMOS, CFHT/MegaCam, Gaia, HST, and JWST data from the HALO7D and NGVS surveys of the Milky Way, the SPLASH, PHAT, and PHAST surveys of M31, and the TREX and PHATTER surveys of M33. Highlights from these surveys include the discovery of the most distant RR Lyrae in the Galaxy's halo (R ~ 300 kpc), constraints on the accretion history of the Galaxy's inner halo (R ~ 25 kpc) via pencil beam studies of main sequence turnoff stars in 7-dimensional space, the discovery of a dynamically hot inner halo population in M33, age-velocity dispersion trends in the stellar disk of M31 and M33, and the M32-M31 interaction.