Poster abstract details
PN abundance determinations -- A view from 1D-RHD simulations
Abstract
During the last years radiation-hydrodynamics simulations have become a powerful tool for understanding formation and evolution of planetary nebulae in terms of simple morphologies and kinematics.
Contrary to photo-ionisation models (with their ad-hoc assumptions of their structure and physics) the RHD models are fully internally consistent with respect to their density distribution, velocity field, and chemical composition. Thus, we use our models as simple proxies for real objects and test the reliability of several aspects of abundance determinations that are based on either plasma diagnostics or static photo-ionisation codes. We discuss effects of non-compliance to thermal and/or ionisation equilibrium, and test the accuracy of various ionisation-correction-factor schemes. This allows us to argue inter alia the sulphur anomaly not to be genuine, despite its recent ``confirmation'' by infrared observations.
Contrary to photo-ionisation models (with their ad-hoc assumptions of their structure and physics) the RHD models are fully internally consistent with respect to their density distribution, velocity field, and chemical composition. Thus, we use our models as simple proxies for real objects and test the reliability of several aspects of abundance determinations that are based on either plasma diagnostics or static photo-ionisation codes. We discuss effects of non-compliance to thermal and/or ionisation equilibrium, and test the accuracy of various ionisation-correction-factor schemes. This allows us to argue inter alia the sulphur anomaly not to be genuine, despite its recent ``confirmation'' by infrared observations.