Physical Sciences and Mathematics Commons^™

New Insights Into Galaxy Structure From Galphat– I. Motivation, Methodology And Benchmarks For Sérsic Models, I Yoon, M Weinberg, N Katz

Astronomy Department Faculty Publication Series

We introduce a new galaxy image decomposition tool, galphat (GALaxy PHotometric ATtributes), which is a front-end application of the Bayesian Inference Engine (bie), a parallel Markov chain Monte Carlo package, to provide full posterior probability distributions and reliable confidence intervals for all model parameters. The bie relies on galphat to compute the likelihood function. galphat generates scale-free cumulative image tables for the desired model family with precise error control. Interpolation of this table yields accurate pixellated images with any centre, scale and inclination angle. galphat then rotates the image by position angle using a Fourier shift theorem, yielding high-speed, accurate …