The rest of the day was spent working out a coordinate transformation to change the perspective of the simulation to one inside the disk of the galaxy. Basically, I'm re-centering the galaxy and then converting from x, y and z to R, Right Ascension and Dec. I think I've got that solved (though I worry it may be too simplistic), but I won't know until I can fix up a rogue for-loop, which shouldn't take too long, but I'd like to eat dinner and see some sun first. Next on the plate is decomposing the motion into radial velocity and proper motion, and then rotating the galaxy so when we do change perspectives everything's aligned. In addition, I've got some nice reading to do about the "Field of Streams" among other things.
Wednesday, June 2, 2010
So, today was fairly productive. I skimmed a few papers about RR Lyrae frequency in globular clusters, and quickly determined that an S of 5.6 meant an average of 5.6 stars per cluster luminosity, so now those numbers make sense. I also saw some of Stephon's talk, but had to duck out after an hour when I figured how to fix the coordinate change I'll go into below.