Tracking spin-axis orbital alignment in selected binary systems: the Torun Rossiter–McLaughlin effect survey
| Autor: | S. K. Kozłowski, Agnieszka Sybilska, Krzysztof G. Hełminiak, Maciej Konacki, Rafał Pawłaszek, P. Sybilski, M. Ratajczak |
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| Rok vydání: | 2018 |
| Předmět: |
Physics
Orbital elements 010308 nuclear & particles physics Rossiter–McLaughlin effect FOS: Physical sciences Astronomy and Astrophysics Astrophysics 01 natural sciences Redshift Spectral line Stars Tilt (optics) Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Spin-½ Eclipse |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 478:1942-1967 |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/sty1135 |
| Popis: | We have obtained high-resolution spectra of four eclipsing binary systems (FM Leo, NN Del, V963 Cen and AI Phe) with the view to gaining insight into the relative orientation of their stellar spin axes and orbital axes. The so called Rossiter-McLaughlin (RM) effect, i.e. the fact that the broadening and the amount of blue- or redshift in the spectra during an eclipse depend on the tilt of the spin axis of the background star, has the potential of reconciling observations and theoretical models if such a tilt is found. We analyse the RM effect by disentangling the spectra, removing the front component and measuring the remaining, distorted lines with a broadening function (BF) obtained from single value decomposition (SVD), weighting by the intensity centre of the BF in the eclipse. All but one of our objects show no significant misalignment, suggesting that aligned systems are dominant. We provide stellar as well as orbital parameters for our systems. With five measured spin-orbit angles we significantly increase (from 9 to 14) the number of stars for which it has been measured. The spin-orbit angle $\beta$ calculated for AI Phe's secondary component shows a misalignment of 87$\pm$17 degrees. NN Del, with a large separation of components and a long dynamical timescale for circularisation and synchronisation, is an example of a close to primordial spin-orbit angle measurement. Comment: 30 pages, 15 figures |
| Databáze: | OpenAIRE |
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