研究成果藝廊
Binary nature revealed in a spiral pattern of AFGL 3068
A model comparison with an observed pinwheel spiral pattern of AFGL 3068: (a) The original Hubble Space Telescope image (Mauron & Huggins 2006), (b) the observed image overlaid with a hydrodynamic model, (c) the result of the hydrodynamic simulation in density distribution, and (d) in column density distribution.
Near the end of a star's life, low to intermediate mass stars return a large fraction of their mass to interstellar space by means of slow dense winds during the asymptotic giant branch (AGB) phase. Recent high resolution observations show nearly concentric patterns in the shape of arcs, rings, and spirals in the circumstellar envelopes of these stars. Based on a comprehensive parameter study of hydrodynamic simulations (Kim & Taam 2012, ApJ, 759, 59), such patterns can be understood in the context of spiral-shell patterns due to the orbital motion of an AGB star and its companion. For the first time, account is taken of the inclination angle with respect to the orbital plane and the overall oblate spheroidal morphology of the spiral-shell pattern, in order to develop a method for constraining the binary characteristics using a parameter space analysis (Kim & Taam 2012, ApJL, 759, 22).