1. A 6-d View of Stellar Shells
- Author
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Eugene Vasiliev, C. A. Dong-Páez, and N. W. Evans
- Subjects
Physics ,Milky Way ,Shell (structure) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Galaxy merger ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Stars ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Stripping (linguistics) ,Halo ,Surface brightness ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
Stellar shells are low surface brightness features, created during nearly head-on galaxy mergers from the debris of the tidally disrupted satellite. Here, we investigate the formation and evolution mechanism of shells in six dimensions (3d positions and velocities). We propose a new description in action-angle coordinates which condenses the seemingly complex behaviour of an expanding shell system into a simple picture, and stresses the crucial role of the existence of different stripping episodes in the properties of shells. Based on our findings, we construct a method for constraining the potential of the host galaxy and the average epoch of stripping. The method is applicable even if the shells cannot be identified or isolated from the data, or if the data are heavily contaminated with additional foreground stars. These results open up a new possibility to study the ancient merger that built the Milky Way Galaxy's stellar halo., Comment: matches published version
- Published
- 2021
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