Recently, large-scale sky surveys and deep follow-up images have discovered a wealth of tidal debris around our Galaxy and others nearby. This debris can give clues to the shapes and masses of the dark matter haloes surrounding these galaxies, as well as those of the dwarf galaxies that were tidally disrupted to form the debris. The class of tidal features known variously as ``shells'' or ``umbrellas" comprises debris that has arisen from minor (high-mass-ratio) mergers with low orbital angular momentum; the nearly radial orbits of the debris give rise to a unique shape and a universal radial density profile. The profile takes this form because the dynamics of the debris can be described by a modified version of the mathematical theory of caustics. Based on this universality, I present a new method for constraining multiple parameters of a minor merger in an external galaxy using only the two-dimensional image of the debris.
|Journal||Bulletin of the American Astronomical Society|
|Publication status||Published - 2011|
|Event||American Astronomical Society, AAS Meeting #218, #123.01 - Boston, Massachusetts, United States|
Duration: 22-May-2011 → 26-May-2011