Wednesday, April 18, 2012

NSAtlas, surface photometry

I wrote some [terribly inefficient, as of now] code for searching NASA Sloan Atlas, given a ra and dec of a galaxy. Just like I expected, my photometry results (SDSS r band) fall somewhere in between the original SDSS photometry and Sloan Atlas (they re-did the photometry, using more sophisticated sky-fitting techniques). And I am still unsure if mine makes sense. Just a good point illustrating the lesson from the previous post: due to the sheer number of pixels in the outskirts of the galaxy, the fine systematic differences on where to stop integrating give rise to significant variations in the final brightness.

No comments:

Post a Comment