[Previous] | [Session 89] | [Next]
T.-H. Lee, S. Kwok (University of Calgary)
We present an indirect method to probe the dust distribution in PNe. Using the free-free continuum flux density and H\beta recombination line flux relationship and the theoretical H\alpha/H\beta line ratio, we determined the expected H\alpha flux from the radio continuum maps. The dust optical depth distribution of each planetary nebula was then derived from the expected to observed H\alpha flux ratio. With HST WFPC2 and VLA A-array observations, dust optical depth maps with resolution as high as ~ 0.1 arcsec can be obtained. The radio continuum images, H\alpha images, and the resultant dust extinction maps were then analyzed in terms of the ellipsoidal shell (ES) model. Simulated radio images are produced using various asymmetry parameters in the ES model. A dust distribution of constant gas-to-dust ratio was given in the model with the same set of asymmetry parameters to simulate the optical and extinction images. These models enable us to remove the projection effects onto the sky, reconstruct the three dimensional dust distribution in planetary nebulae, and make quantitative measures of the intrinsic asymmetries of the nebulae.
The author(s) of this abstract have provided an email address for comments about the abstract: thlee@iras.ucalgary.ca
[Previous] | [Session 89] | [Next]
Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.