In this project you will study the outer structure of dwarf galaxies, searching for evidence of possible past interactions. The dwarfs available for study are companions to the Milky Way such as the Fornax and Sculptor dwarf Spheroidal galaxies, and Local Group dwarfs such as the dwarf irregular NGC 6822. Wide field imaging data are available from the DECam (CTIO 4m telescope) and MegaCam (Magellan 6.5m telescope) digital cameras. You will use digital photometry techniques to determine the outer structure of these systems, searching for evidence of stellar streams and asymmetries that would indicate a past history of interactions with the Milky Way or other large galaxies. A particular target is NGC 6822 in which the old stars are aligned almost perpendicular to the gas and young stars. This dwarf galaxy may be the nearest example of a ‘polar-ring’ galaxy, which are generally thought to arise as a result of galaxy interactions.