Models of the Hydrodynamic Histories of Post-AGB Stars. I. Multiflow Shaping of OH 231.8+04.2
- Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States)
- Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States)
- Center for Advanced Comp and Data Systems, University of Houston, 4718 Calhoun Rd., Houston, TX 77204-3058 (United States)
We present a detailed hydrodynamic model that matches the present structure of the well-observed preplanetary nebula (“pPN”) OH 231.8+04.2 (“OH231”). The purpose of the model is to present a physically justified and coherent picture of its evolutionary history from about 100 years from the start of the formation of its complex outer structures to the present. We have adopted a set of initial conditions that are heavily constrained by high-quality observations of its present structure and kinematics. The shaping of the nebula occurs while the densities of the flows are “light,” i.e., less than the surrounding AGB-wind environment. The simulations show that pairs of essentially coeval clumps and sprays of the same extent and density, but different outflow speeds, sculpted both the pair of thin axial flow “or spine” and the bulbs. The total ejected mass and momentum in the best-fit model are surprisingly large—3 M {sub ⊙} and 2.2 × 10{sup 41} gm cm s{sup −1}, respectively—however, these values are reduced by up to a factor of 10 in other models that fit the data almost as well. Our ultimate goal is to combine the present model results of masses, momenta, flow speeds, and flow geometries for OH231 with those of other models to be published in the future in order to find common attributes of their ejection histories.
- OSTI ID:
- 22663414
- Journal Information:
- Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 843; ISSN ASJOAB; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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