The satellite-disk interaction provides limits on halo properties in two
ways: (1) physical arguments motivate the excitation of observable Galactic
disk structure in the presence of a massive halo, although precise limits on
halo parameters are scenario-dependent; (2) conversely, the Milky Way as a
whole has significant dynamical effect on LMC structure and this interaction
also leads to halo limits. Together, these scenarios give strong corroboration
of our current gravitational mass estimates and suggests a rapidly evolving
LMC.Comment: 12 pages, 8 Postscript figures, uses paspconf.sty. To appear in the
  Third Stromlo Symposium: The Galactic Halo (ASP Conference Series), in press.
  HTML version available at: http://www-astro.phast.umass.edu/~weinberg/stroml

Weinberg, Martin D.

English

arXiv

This is a pre-published version which is collected from arXiv link. The published version is at http://www.aspbooks.org/a/volumes/article_details/?paper_id=17091We 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)100-11

Weinberg, Martin D

ScholarWorks@UMass Amherst

Effect Of The Magellanic Clouds On The Milky Way Disk And Vice Versa

This paper was harvested from ArXiv identifier is arXiv:9811204v1The satellite-disk interaction provides limits on halo properties in two ways: (1) physical arguments motivate the excitation of observable Galactic disk structure in the presence of a massive halo, although precise limits on halo parameters are scenario-dependent; (2) conversely, the Milky Way as a whole has significant dynamical effect on LMC structure and this interaction also leads to halo limits. Together, these scenarios give strong corroboration of our current gravitational mass estimates and suggests a rapidly evolving LMC

The satellite-disk interaction provides limits on halo properties in two ways: (1) physical arguments motivate the excitation of observable Galactic disk structure in the presence of a massive halo, although precise limits on halo parameters are scenario-dependent; (2) conversely, the Milky Way as a whole has significant dynamical effect on LMC structure and this interaction also leads to halo limits. Together, these scenarios give strong corroboration of our current gravitational mass estimates and suggests a rapidly evolving LMC

Effect of the Magellanic Clouds on the Milky Way Disk and VICE VERSA

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

Effect of the Magellanic Clouds on the Milky Way disk and VICE VERSA

https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1109&amp;context=astro_faculty_pubs

Effect of the Magellanic Clouds on the Milky Way disk and VICE VERSA

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