Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:We present the results of a new H I, optical, and H-alpha interferometric study of the nearby spiral galaxy NGC 157. Our combined C- and D-array observations with the VLA show a large-scale, ringlike structure in the neutral hydrogen underlying the optical disk, together with an extended, low-surface density component going out to nearly twice the Holmberg radius. Beginning just inside the edge of the star-forming disk, the line of nodes in the gas disk commences a 60 deg warp, while at the same time, the rotation velocity drops by almost half its peak value of 200 km/s, before levelling off again in the outer parts. While a flat rotation curve in NGC 157 cannot be ruled out, supportive evidence for an abrupt decline comes from the ionized gas kinematics, the optical surface photometry, and the global HI profile. A standard 'maximum-disk' mass model predicts comparable amounts of dark and luminous matter within NGC 157. Alternatively, a model employing a disk truncated at two disk scalelengths could equally well account for the unusual form of the rotation curve in NGC 157.