Galactic halo stellar structures in the triangulum-andromeda region

This Letter reports on the Galactic stellar structures that appear in the foreground of our Canada-France-Hawaii-Telecopse/ MegaCam survey of the halo of the Andromeda galaxy. We recover the main sequence and main-sequence turnoff of the Triangulum- Andromeda structure recently found by Majewski and collaborators at a heliocentric distance of similar to 20 kpc. The survey also reveals another less populated main sequence at fainter magnitudes that could correspond to a more distant stellar structure at similar to 28 kpc. Both structures are smoothly distributed over the similar to 76 deg(2) covered by the survey, although the closer one shows an increase in density by a factor of similar to 2 toward the northwest. The discovery of a stellar structure behind the Triangulum- Andromeda structure that itself appears behind the low- latitude stream that surrounds the Galactic disk gives further evidence that the inner halo of the Milky Way is of a spatially clumpy nature.