Modeling with the Advanced Science Analysis Package (ASAP)

Abstract

ASAP is a project initiated at the MPIfR which aims at providing a new generation of scientific analysis tools to extract the physical information from the high dynamical range data of current and future instruments. It was motivated by the ALMA project but the concepts and their implementations are applicable to all wavelengths. This presentation is focused on DALIA (Direct Aproach to spectral Line Analysis), a prototype software for forward modeling. It consists of a JAVA graphical user interface through which the user can fit models to observations. The models are stored as binaries and are described by XML files according to a schema. New models developed in any language can thus be easily added to the model database by the user. The different steps of the fit (simulation, evaluation, parameter change) can be executed manually or automatically through an optimization engine. The interface allows the user to have a direct control on the model parameters which can be fixed or constrained. The data to be modeled can be of any type (1D, 2D, 3D, specral, spatial, temporal...) and associations of datasets of different types are supported as long as the axes are identical to those of the model output. In this prototype the FITS format is supported. For spectral synthesis, the spectroscopic data from the molecular databases (Cologne, JPL) are used. This approach is very generic and uses concepts similar to those of the Virtual Observatory. Its integration into the VO would allow astronomers to use the data archives to constrain a model and would permit to store model solutions for each source. These model solutions could thus be easily shared and be improved with the aquisition of new data.