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Circumnuclear stellar and gaseous disks in bulge-dominated disk galaxiesстатья
Информация о цитировании статьи получена из
Web of Science
Дата последнего поиска статьи во внешних источниках: 29 мая 2015 г.
- Автор: Sil’Chenko O.K.
- Сборник: The Interplay Among Black Holes, Stars and ISM in Galactic Nuclei
- Серия: IAU Symposium
- Том: 222
- Год издания: 2004
- Издательство: Cambridge University Press
- Местоположение издательства: United Kingdom
- Первая страница: 209
- Последняя страница: 210
- DOI: 10.1017/S174392130400208X
- Аннотация: When studying the central regions of early-type (bulge-dominated) disk galaxies by means of 2D spectroscopy, we have found a lot of chemically and kinematically decoupled cores which are mostly compact circumnuclear disks. These disks are formed in some secondary star formation bursts, because their stellar populations are in average younger than the stars of their surrounding bulges; and their planes are often inclined to the main symmetry planes of the outer large-scale disks. We are able to prove that the observed substructures are axisymmetric disks and not nuclear bars, because the photometric major axis of the central isophotes and the kinematical major axis of the stellar velocity fields are aligned. Their inclination to the main symmetry plane remains to be explained. The circumnuclear GASEOUS disks are often decoupled from the circumnuclear stellar disks and are even stronger inclined to the outer disk planes; in fact, we have found a considerable `population' of inner polar rings. Inner gas polar rings are found as in spiral galaxies with the massive outer gas disks co-planar to the main symmetry planes (e.g. NGC 2841 and NGC 7217) as well in many lenticular galaxies. However, the latters are unusually HI-rich lenticulars, and the orientations of the outer gas rings/disks appear to be decoupled from the inner polar rings. So we think that polar orientation of the inner gas rings has nothing to do with the external gas accretion but rather relates to bars or other triaxial structures in the galaxies under consideration.
- Добавил в систему: Сильченко Ольга Касьяновна