Optical kinematics in the Cygnus Loop. II. Interpretation.
Abstract
Imaging Fabry-Perot observations in the lines of H alpha and O III were made of selected regions in the Cygnus Loop supernova remnant and a summary of the observations is given. Observations of the small-scale radial velocity structure of optical filaments are discussed and consideration is given to interpretation of the gas kinematics. The cloud model and radiative-sheet model are reviewed and it is concluded that the optical kinematics of the Cygnus Loop bear a greater resemblance to the radiative-sheet model. It is suggested that a narrow O III component is associated with the remnant and may be due to photoionized gas in the precursor region. This component allows the estimation of the systemic velocity of the Cygnus Loop and the derivation of a kinematic distance.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 1992
- Bibcode:
- 1992A&A...257..265G
- Keywords:
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- Image Analysis;
- Kinematics;
- Supernova Remnants;
- Adiabatic Conditions;
- Emission Spectra;
- H Alpha Line;
- Radiative Heat Transfer;
- Shock Fronts;
- Astrophysics