The Conelike Hα Nebula in NGC 4945: A Galactic Superwind Bow Shock?
Open Access
- 10 April 1997
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 479 (1) , L23-L26
- https://doi.org/10.1086/310582
Abstract
We find that a nonaxisymmetric bow shock model, with an appropriate choice of parameters, could fit the line-splitting velocity field of the conelike Hα nebula in NGC 4945 better than a canonical cone model. Meanwhile, the bow shock model could also reproduce the morphology of the Hα nebula. The bow shock results from the interaction of the galactic superwinds with a giant H II region. It is implied that the starburst ring or disk around the galactic nucleus should be generating strong winds, and the bright Hα knot northwest of the nucleus should be suffering an anisotropic mass-loss process.Keywords
All Related Versions
This publication has 10 references indexed in Scilit:
- Exact, Algebraic Solutions of the Thin-Shell Two-Wind Interaction ProblemThe Astrophysical Journal, 1996
- Spectral Signatures of Fast Shocks. II. Optical Diagnostic DiagramsThe Astrophysical Journal, 1995
- On the wind-powered nebula NGC 2359 and the WN star HD 56925The Astrophysical Journal, 1995
- Dynamics and X-ray emission of a galactic superwind interacting with disk and halo gasThe Astrophysical Journal, 1994
- Extended infrared line emission excited by starburst and Seyfert activity in NGC 3256 and NGC 4945The Astrophysical Journal, 1994
- A Reevaluation of the Excitation Mechanism of LINERsThe Astrophysical Journal, 1993
- On the nature and implications of starburst-driven galactic superwindsThe Astrophysical Journal Supplement Series, 1990
- Active Galactic NucleiPublished by Springer Nature ,1989
- Discovery of a nebula around PSR1957 + 20Nature, 1988
- The Dynamical Evolution of H II Regions—Recent Theoretical DevelopmentsAnnual Review of Astronomy and Astrophysics, 1986