Panchromatic Hubble Andromeda Treasury. XIX. The Ancient Star Formation History of the M31 Disk

Benjamin F. Williams, Andrew E. Dolphin, Julianne J. Dalcanton +7

We map the star formation history across M31 by fitting stellar evolution models to color-magnitude diagrams of each 83${}^{\prime \prime }\times$83${}^{\prime \prime }$ (0.3$\times$1.4 kpc, deprojected) region o…