I'm close to submitting my MSc thesis. The analysis has really come together well, and I have sorted out (I hope) most of the errors in it. I hope to submit it within a week or two.
So the main point is that the Triangulum Galaxy has interacted with Andromeda, and a load of material has been stripped off the Triangulum (smaller) galaxy as it has gravitationally interacted with the larger Andromeda galaxy. I'm looking at that in a new way, using spectroscopic observations to select stars based on their radial velocity (as determined by their Doppler shift). Then once this selection is made, any differences in composition (what we call metallicity in astronomy) can be measured, although for individual stars in Triangulum galaxy, these measurements are not all that accurate.