engleski

Modern Techniques for the Analysis of Spectroscopic Binaries

Spectroscopic binaries are fundamental sources of precise basic stellar parameters. Composite spectra of multiple systems are used to determine orbital parameters, and more recently to reconstruct component spectra. Techniques used to obtain these goals include measurement of positions of single spectral lines, cross-correlation using template spectra or hardware masks, two-dimensional cross-correlation, determination of broadening functions, subtraction of a template for the primary component, Doppler tomography, spectral separation and spectral disentangling. An overview of these techniques will be given pointing out relations between them, basic limitations, strengths and, when appropriate, implications for the observing strategy. The second part of the talk will be devoted to a more detailed discussion of spectral separation and disentangling techniques using either the Fourier components of the composite spectra or their representation in velocity (logarithmic wavelength) space, with the aim to give the potential user insight in equivalence and practical differences between different approaches. An evaluation of the risks due to near-singularity of the involved equations and due to bias in the observations is made in the case of spectral separation of binary stars.

binary stars; spectroscopy; radial velocity

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