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Effect of the Magellanic Clouds on the Milky Way disk and VICE VERSA
Third Stromlo Symposium: The Galactic Halo
  • Martin D Weinberg, University of Massachusetts - Amherst
Publication Date
We introduce a new galaxy image decomposition tool, GALPHAT (GALaxy PHotometric ATtributes), to provide full posterior probability distributions and reliable confidence intervals for all model parameters. GALPHAT is designed to yield a high speed and accurate likelihood computation, using grid interpolation and Fourier rotation. We benchmark this approach using an ensemble of simulated Sersic model galaxies over a wide range of observational conditions: the signal-to-noise ratio S/N, the ratio of galaxy size to the PSF and the image size, and errors in the assumed PSF; and a range of structural parameters: the half-light radius $r_e$ and the Sersic index $n$. We characterise the strength of parameter covariance in Sersic model, which increases with S/N and $n$, and the results strongly motivate the need for the full posterior probability distribution in galaxy morphology analyses and later inferences. The test results for simulated galaxies successfully demonstrate that, with a careful choice of Markov chain Monte Carlo algorithms and fast model image generation, GALPHAT is a powerful analysis tool for reliably inferring morphological parameters from a large ensemble of galaxies over a wide range of different observational conditions. (abridged)
This is a pre-published version which is collected from arXiv link. The published version is at
Book Series Title
Astronomical Society of the Pacific Conference Series
Citation Information
Martin D Weinberg. "Effect of the Magellanic Clouds on the Milky Way disk and VICE VERSA" Third Stromlo Symposium: The Galactic Halo Vol. 165 (1999)
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