Poster abstract details
Radiative Transfer models of 21 and 30micron features in five C rich PPNe
Abstract
The 21\mu and 30\mu emission features are the strongest dust emission features detected in the C rich PPNs which together account more than 20 \% of the total IR flux. The required atomic abundances in the carriers to account for the total power emitted by the spectral features should be consistent with their stellar photospheric values. Using DUSTY, we have made 1D radiative transfer models for five C rich PPNs which show strong emission features at 21 and 30 micron; namely IRAS 07134+1005, IRAS 16594-4656,IRAS 19500-1709,IRAS 22272+5435 and IRAS 23304+6147 .
Taking FeO and MgS respectively are the carriers of the 21\mu and 30\mu features, we derived the atomic abundances of Fe, Mg and S locked up in the circumstellar grains. The required atomic abundances in the circumstellar envelope are smaller than their stellar photospheric values available in the literature. Dust shell mass, temperature and the mass-loss rate were derived for these five PPNs and were compared with the values published .
Taking FeO and MgS respectively are the carriers of the 21\mu and 30\mu features, we derived the atomic abundances of Fe, Mg and S locked up in the circumstellar grains. The required atomic abundances in the circumstellar envelope are smaller than their stellar photospheric values available in the literature. Dust shell mass, temperature and the mass-loss rate were derived for these five PPNs and were compared with the values published .