Realistic Multimedia Tools based on Physical Models: I. The Spectrum Analyzer and Animator (SA2)
This work addresses the challenge of analyzing composite stellar winds in astrophysics, but it is incremental as it builds on existing tomographic techniques applied to a specific domain.
The authors tackled the problem of simulating and visualizing the 3D wind structure of hot close double stars, which cannot be spatially resolved, by developing a toolkit that automates the derivation of light curves from observed spectra and generates synthetic wind-line profiles to match observed variabilities.
The present sequence of two articles reports on a custom-built toolkit implementing a technique similar to multi-directional medical tomography to simulate and visualize the composite 3D structure of winds from hot close double stars. In such hot binaries, the light sources scanning and probing 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 (SA 2 ) and the Binary 3D Renderer (B3dR). The SA 2 is the subject of the present article (paper I). It 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. The second tool, the B3dR is discussed in paper II.