Modeling the IR spectrum of the dust shell around the [WC] star: V605 AQL

Nebulae around low mass Wolf-Rayet [WC] stars often show a strong mid and n ear infrared (MN-IR) emission which cannot be explained with a single grain size and an equilibrium temperature model. We investigated the effect of t he grain size, radiation density, and temperature fluctuations of small dus t grains on the spectral energy distribution (SED) in the infrared. A model of ISOCAM and IRAS measurements of V605 Aql (Kimeswenger et al., 1998) has been computed using a gas-dust combination model including transiently hea ted particles. Our calculations show that the central knot in V605 Aql (Abe ll 58) is too compact or just on the lower boundary that temperature fluctu ations really have to be considered in model calculations for the infrared SED.