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Интеллектуальная Система Тематического Исследования НАукометрических данных |
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Spectral Investigation of NGC 7469 Using Image-Tube Observations from 1972-1990статья
Дата последнего поиска статьи во внешних источниках: 28 мая 2015 г.
- Авторы: Doroshenko V.T., Sergeev S.G., Chuvaev K.K.
- Журнал: Astronomy Reports
- Том: 38
- Год издания: 1994
- Издательство: Maik Nauka/Interperiodica Publishing
- Местоположение издательства: Russian Federation
- Первая страница: 200
- Аннотация: This investigation is mainly related to hydrogen lines in the spectrum of NGC 7469 from the 1972- 1990 data obtained using a image tube on the 2.6m telescope of the Crimean Astrophysical Observatory. The decomposition of the hydrogen lines into broad and narrow components was performed. Variations in the intensities and broad-component contours were observed. One third of the spectrograms showed a broad, symmetric Halpha_ line, while the others showed asymmetry: the blue wings fall more steeply than the red ones. The degree of asymmetry is variable, but no correlation between it and the brightness of the nucleus was found. This asymmetry becomes weaker when passing to higher members of the Balmer series. The halfwidths of the broad components increase from Halpha_ to Hgamma_. Redshifts of broad components with respect to narrow ones might also be larger for higher members of the Balmer series. Intensities of the broad hydrogen lines follow continuum variations with a delay of about 28 days. The Balmer decrement for broad lines is much flatter than for narrow ones. These results may be accepted if one agrees that effective radiation in the broad hydrogen lines is emitted from the denser parts of the broad-line region (BLR) where n_e_ >= 10^11^ cm^-3^ and the high-density clouds are situated closer to the central engines than the low-density clouds, which are situated on the periphery of regions that emit broad hydrogen lines.
- Добавил в систему: Дорошенко Валентина Трофимовна