New test of bow-shock models of Herbig-Haro objects
Long-slit, high-resolution spectroscopy of the Herbig-Haro oject HH 32 has shown that the emission-line profiles in all four condensations A, B, C, and D show high- and low-velocity components. The spatial maxima of these two components are always arranged in a double-layer pattern, with the maximum of the high-velocity component 0.6-1.0 arcsecs closer to the central star (AS 353A) than the low-velocity maximum. A study of the emission-line profiles predicted from a model of a radiating bow shock shows that such a double-layer structure appears naturally for this type of flow. In this case both the high-velocity and the low-velocity components come from the post-shock gas, in agreement with the theoretical prediction that it should be very difficult to detect the pre-shock gas observationally. The present results agree qualitatively well with observations of HH 32, strengthening the case for a bow-shock interpretation of this Herbig-Haro object. It is shown that the double-layer effect will be more easily observable for bow shocks which move at a relatively large angle with respect to the plane of the sky (i.e., for Herbig-Haro objects which have large radial velocities). 31 references.
- Research Organization:
- Washington Univ., Seattle; Max-Planck-Institut fuer Astronomie, Heidelberg, West Germany
- OSTI ID:
- 7012797
- Journal Information:
- Astron. J.; (United States), Journal Name: Astron. J.; (United States) Vol. 92; ISSN ANJOA
- Country of Publication:
- United States
- Language:
- English
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