Notes on disentangling of spectra II. Intrinsic line-profile variability due to Cepheid pulsations - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate




Notes on disentangling of spectra II. Intrinsic line-profile variability due to Cepheid pulsations - Astrophysics > Solar and Stellar Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: The determination of pulsation velocities from observed spectra of Cepheidsis needed for the Baade-Wesselink calibration of these primary distancemarkers. The applicability of the Fourier-disentangling technique for thedetermination of pulsation velocities of Cepheids and other pulsating stars isstudied. The KOREL-code was modified to enable fitting of free parameters of aprescribed line-profile broadening function corresponding to the radialpulsations of the stellar atmosphere. It was applied to spectra of delta Cep inthe H-alpha region observed with the Ondrejov 2-m telescope. The telluric lineswere removed using template-constrained disentangling, phase-locked variationsof line-strengths were measured and the curves of pulsational velocitiesobtained for several spectral lines. It is shown that the amplitude and phaseof the velocities and line-strength variations depend on the depth of lineformation and the excitation potential. The disentangling of pulsations in theCepheid spectra may be used for distance determination.



Author: P. Hadrava, M. Slechta, P. Skoda

Source: https://arxiv.org/



DOWNLOAD PDF




Related documents