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Paper: |
High Resolution Spectroscopy of the Nuclei of the Bipolar Planetary Nebulae M 2-9 and M 1-91 |
Volume: |
199, Asymmetrical Planetary Nebulae II: From Origins to Microstructures |
Page: |
255 |
Authors: |
Arrieta, Anabel; Torres-Peimbert, Silvia |
Abstract: |
We have analyzed high resolution echelle spectra of the nuclei of the young planetary nebulae M2-9 and M1-91. In M2-9 there is a well defined negative gradient of ionization potential, electron density, electron temperature and gas pressure with radial velocity. This behavior can be interpreted as a negative gradient in these parameters with distance to the exciting star. M1-91 shows a similar behavior. For M2-9 and M1-91 the intensity of Hα is higher than expected under photoionized conditions. We suggest that shock excitation populates the lower levels of hydrogen. Both objects show extremely wide wings in Hα (of several 103 km s-1). We attribute these extended wings to electron scattering. These observations support the interacting stellar winds model. |
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