Realistic multimedia: from physical models to Instructive multimedia content

Abstract

Multimedia technologies are invaluable in generating realistic content and applications which increase the effectiveness and communication impact of research results. The functional keyword “realistic” means content that is based on physical modeling and, therefore, is physically sound. The present article reports on a novel custom-built toolkit intended to train budding astronomers into simulating and visualizing the composite 3D structure of winds from hot close double stars by implementing a technique which is similar to multi-directional medical tomography. In such hot binaries, the light sources that scan and probe the composite wind volume are the bright “surfaces” (photospheres) of the individual stars. Then, as the Keplerian orbit is traced out and the geometry presented to the observer varies, each star constitutes an analyzer upon its companion's wind. In contrast to medical tomography, however, these targets are too far to be resolved spatially so we resort to modeling the ultraviolet (UV) spectral lines of certain wind ions (e.g., N+4, Si+3, C+3) whose shapes vary with Keplerian phase as the stars revolve around their common centre of mass. The flagships of the toolkit are the Spectrum Analyzer and Animator (SA2) and the Binary 3D Renderer (B3dR). The first tool, the SA2, automates (a) the derivation of light curves from the observed spectra and (b) the generation of synthetic binary wind-line profiles which reproduce the morphologies and variabilities of the observed wind profiles. After the composite wind structure of a binary has been recovered, the B3dR is employed to visualize the results and simulate the revolution of the entire system (stars, winds and wind-interaction effects) around the common centre of mass. The B3dR thus repackages the end product of a lengthy physical modeling process to generate realistic multimedia content and enable the presentation of the 3D system from the point of view of an observer on Earth as well as from any other observer location in the Galaxy.