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High-resolution spectroscopy of the high-velocity hot post-AGB star IRAS 18379–1707 (LS 5112)статья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 10 июня 2020 г.
- Авторы: Ikonnikova N.P., Parthasarathy M., Dodin A.V., Hubrig S., Sarkar G.
- Журнал: Monthly Notices of the Royal Astronomical Society
- Том: 491
- Номер: 4
- Год издания: 2020
- Издательство: Oxford Journals, Oxford University Press
- Местоположение издательства: Oxford, UK, England
- Первая страница: 4829
- Последняя страница: 4842
- DOI: 10.1093/mnras/stz3355
- Аннотация: The high-resolution (R∼48000) optical spectrum of the B-type supergiant LS 5112, identified as the optical counterpart of the post-AGB candidate IRAS 18379–1707 is analysed. We report the detailed identifications of the observed absorption and emission features in the wavelength range 3700–9200 Å for the first time. The absorption line spectrum has been analysed using non-LTE model atmosphere techniques to determine stellar atmospheric parameters and chemical composition. We estimate Teff = 18 000 ± 1000 K, log g = 2.25 ± 0.08, ξt = 10 ± 4 km s−1, and vsin i = 37 ± 6 km s−1, and the derived abundances indicate a metal-deficient ([M/H] ≈ −0.6) post-AGB star. Chemical abundances of eight different elements were obtained. The estimates of the CNO abundances in IRAS 18379–1707 indicate that these elements are overabundant with [(C + N + O)/S] = + 0.5 ± 0.2 suggesting that the products of helium burning have been brought to the surface as a result of third dredge-up on the AGB. From the absorption lines, we derived heliocentric radial velocity of Vr = −124.0 ± 0.4 km s−1. We have identified permitted emission lines of O I, N I, Na I, S II, Si II, C II, Mg II, and Fe III. The nebula forbidden lines of [N I], [O I], [Fe II], [N II], [S II], [Ni II], and [Cr II] have also been identified. The Balmer lines H α, H β, and H γ show P-Cygni behaviour clearly indicating post-AGB mass-loss process in the object with the wind velocity up to 170 km s−1.
- Добавил в систему: Иконникова Наталия Петровна