On the Nebular Motions of Sharpless 2-106 and its Evolutionary Phase

Undergraduate Honors Thesis

Citations

Citeable URL: https://scholar.colorado.edu/concern/undergraduate_honors_theses/fx719n336

Abstract

Various details of the mechanisms and transitions that occur during massive star formation elude the scientific community due to inherent observational limitations. Sharpless 2-106 (S106) provides an opportunity to study the transitionary phases in massive star formation. S106 exhibits bipolar morphology, and has unprecedentedly fast nebular proper motions of up to ~120 kms-1, many times the sound speed in photo-ionized plasma. Velocity analysis of the S106 nebula is presented to allow for classification of its evolutionary state. Data implies a transitionary state, and demonstrates nebular proper motions increasing with distance from the ionizing source. This points to three possible models: [1] The central star, S106 IR, may have experienced an explosion a few millennia ago that initiated the nebular motions. [2] The nebular motions may be associated with a dense expanding shell produced by stellar winds. [3] The evolving nebula consists of recently ionized ejecta, launched during a bipolar-molecular outflow phase during accretion.

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