precision and accuracy, post-aperture photometry

At Columbia today I met up with Bonaca and Price-Whelan and Johnston and Küpper. Bonaca has nearly finished a paper that asks what might be going wrong when we fit the Milky Way potential with a smooth, time-invariant, analytic model, which does not include all the messiness of substructure, mass accretion, and radial gradients of triaxiality. We discussed the issue that there is no really principled way to distinguish these different kinds of messiness; they are all just slightly different aspects of the same fundamental messiness, and they overlap substantially.

Price-Whelan has nearly finished a paper that looks at how we can make inferences about the Milky Way using small numbers of extremely well-measured stars in tidal streams. Bonaca's paper is about accuracy, and Price-Whelan's is about precision.

Late in the day I finished (or, really, started) testing (on real Kepler data no less) my method for making a generalization of aperture photometry that is much more precise. It works extremely well! I now want to combine it (unfortunately) with data-driven focal-plane calibration, because I have a (possibly wrong) intuition that it will shine even brighter relative to normal aperture photometry as the calibration gets better.


  1. Regarding "post-aperture" photometry -- are you familiar with Tim Naylor's "optimal photometry" (which is sort of based on Keith Horne's "optimal spectroscopy)?


    Is this similar to what you are trying to do?

  2. Related! Thanks for the links. What I am doing is more general, I think, but I will analyze better asap.

  3. Just read this paper by Naylor -- excellent! I will probably blog it for today...