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We present results from wide-field imaging of the resolved stellarpopulations of the dwarf spheroidal galaxies Cassiopeia III (And XXXII) andPerseus I (And XXXIII), two satellites in the outer stellar halo of theAndromeda galaxy (M31). Our WIYN pODI photometry traces the red giant starpopulation in each galaxy to ~2.5-3 half-light radii from the galaxy center. Weuse the Tip of the Red Giant Branch (TRGB) method to derive distances of(m-M)_0 = 24.62+/-0.12 mag (839 (+48,-450) kpc, or 156 (+16,-13) kpc from M31)for Cas III and 24.47+/-0.13 mag (738 (+48,-45) kpc, or 351 (+17,-16) kpc fromM31) for Per I. These values are consistent within the errors with TRGBdistances derived from a deeper Hubble Space Telescope study of the galaxies'inner regions. For each galaxy, we derive structural parameters, totalmagnitude, and central surface brightness. We also place upper limits on theratio of neutral hydrogen gas mass to optical luminosity, confirming thegas-poor nature of both galaxies. We combine our data set with correspondingdata for the M31 satellite galaxy Lacerta I (And XXXI) from earlier work, andsearch for substructure within the RGB star populations of Cas III, Per I, andLac I. We find an overdense region on the west side of Lac I at a significancelevel of 2.5-3-sigma and a low-significance filament extending in the directionof M31. In Cas III, we identify two modestly significant overdensities near thecenter of the galaxy and another at two half-light radii. Per I shows noevidence for substructure in its RGB star population, which may reflect thisgalaxy's isolated nature.

Exploring the Structures and Substructures of the Andromeda Satellite Dwarf Galaxies Cassiopeia III, Perseus I, and Lacerta I