Understanding Dark Matter Halos with Tidal Caustics

Robyn E. Sanderson*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


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.
Original languageEnglish
JournalBulletin of the American Astronomical Society
Publication statusPublished - 2011
EventAmerican Astronomical Society, AAS Meeting #218, #123.01 - Boston, Massachusetts, United States
Duration: 22-May-201126-May-2011

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