The following document lists the file abstract/SGORNY_SKG_ISO.abs
from catalogue VI/111.
A plain copy of the file
(without headers/trailers) may be downloaded.
From the early days of infrared observations it has been known that the planetary nebulae (PNs) have strong dust emission at far-infrared wavelengths. For well observed IRAS sources on the average about 30% of the total bolometric flux of PNs comes from the dust component which seems to be remnants of the dust shell ejected in the preceding asymptotic giant branch phase of evolution. Properties of nebular dust are related to the overall chemical evolution during AGB and, in particular, could be connected to the phase of nuclear burning at which departure from asymptotic giant branch took place. Fig. 1, based on the IRAS data, suggests that this can be the case. Figure presents locations of planetary nebulae with three different types of central stars: Wolf-Rayet type (WR - hydrogen poor, helium burners), other emission-lines spectra objects (wels) and hydrogen rich central stars (H-rich). Therefore it is desirable to study the dust in PNe to understand its properties and correlation with central star properties. We believe that it would be possible to find out typical characteristics of dust which give us an answer about nature of the central star and in consequence some information about its preceding evolution. In this proposal we seek detailed spectroscopy of the dust emission in selected PNe characterized by strong dust emission and with different spectral types of central stars. The spectral information which the SWS and LWS instruments can provide will for the first time fully characterize the dust emission in these PNe (they are not on the GTO list). Our radiative transfer and photoionization models should allow us to deduce the radial temperature distribution of the dust and its chemical composition.