Published in "Tidal Streams in the Local Group and Beyond: Observations and Implications", Astrophysics and Space Science Library, Volume 420. ISBN 978-3-319-19335-9. Springer International Publishing Switzerland, 2016.
http://arxiv.org/abs/1603.06601

For a PDF version of the article, click here.

ORIGINS AND INTERPRETATION OF TIDAL DEBRIS

Kathryn V. Johnston


Columbia University


Abstract: The stellar debris structures that have been discovered around the Milky Way and other galaxies are thought to be formed from the disruption of satellite stellar systems — dwarf galaxies or globular clusters — by galactic tidal fields. The total stellar mass in these structures is typically tiny compared to the galaxy around which they are found, and it is hence easy to dismiss them as inconsequential. However, they are remarkably useful as probes of a galaxy's history (as described in this chapter) and mass distribution (covered in a companion chapter in this volume). This power is actually a consequence of their apparent insignificance: their low contribution to the overall mass makes the physics that describes them both elegant and simple and this means that their observed properties are relatively easy to understand and interpret.


Table of Contents

INTRODUCTION

ILLUSTRATIVE N-BODY SIMULATIONS

BASIC PRINCIPLES OF DEBRIS FORMATION AND EVOLUTION
Debris spreading: phase-mixingphase mixing
Intuition from spherical potentials
Action-angle formalism
Orbital properties of tidal debris
Application: models of streams
Estimating physical scales in debris
Generating predictions for density distributions along streams

MORPHOLOGIES OF INDIVIDUAL DEBRIS STRUCTURES IN OBSERVABLE CO-ORDINATES
Young debris
Fully phase-mixed debris

DEBRIS IN A COSMOLOGICAL CONTEXT: MODELING AND INTERPRETING PROPERTIES OF STELLAR HALOS
Cosmological simulations of stellar halo formation
General results of cosmological accretion models
Accreted phase-space structure in halos
Accreted stellar populations in halos
Implications and applications
Statistical comparisons with observations
Recovering accretion histories
Accreted populations as a window on galaxy formation over cosmic time

SUMMARY OF STATUS AND PROSPECTS

REFERENCES

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