The applicability of the Fourier convolution theorem to the analysis of late-type stellar spectra

Abstract

view Abstract Citations (28) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The applicability of the Fourier convolution theorem to the analysis of late-type stellar spectra Bruning, D. H. Abstract It is shown using observed solar flux and intensity line profiles that explicit disk integration is more accurate than the Fourier convolution method for the analysis of late-type stellar spectra. The convolution method systematically underestimates or overestimates the line broadening depending upon line strength and incorrectly estimates the line depth. This failure of the convolution method is due to the center-to-limb variation of the line shape across the stellar disk. It is shown, however, that the convolution method is an appropriate approximation for analyzing the spectra of fast rotators as long as rotation is the dominant line-broadening mechanism. Rotational zeros were found for two weak lines leading to a solar rotational velocity of 1.85 + or - 0.1 km/s. These zeros are not visible unless the signal-to-noise ratio is greater than 1000, demonstrating the extreme difficulty of obtaining unique rotational signals from line-profile analysis of late-type stars. Publication: The Astrophysical Journal Pub Date: June 1984 DOI: 10.1086/162162 Bibcode: 1984ApJ...281..830B Keywords: Convolution Integrals; Fourier Analysis; Late Stars; Spectrum Analysis; Stellar Rotation; Stellar Spectra; Fourier Transformation; Line Spectra; Astrophysics full text sources ADS |