影响星系旋转曲线的几个因素

THE INFLUENCE OF SOME FACTORS ON THE ROTATION CURVES OF GALAXIES

本文讨论了可能影响星系旋转曲线的若干因素,特别是星系整体运动和星系内局部运动对旋转曲线的影响。

There are various factors which affect the shape of the curve. In this paper, we will mainly discuss two of them. One is the rotation of the galaxy as a whole round some ex-ternal point which may be the common mass center of the galaxy and its nearby matter. The other is some local disturbance to the galaxies. For example, if the central part of the luminous disk of the galaxy encountered some disturbance (e.g. emitting some jetlike matter or so), it could acquire a velocity, and then bring other parts to move. Therefore, there would be a velocity distribution throughout the whole galaxy with the maximum at the center. This distribution gives additional velocity being different (relative to the rotation of the galaxy kself) In different directions.In the recent observation by. Rubin and Ford on the galaxy Hickson 88a, not only the rotation curve appears to be inclined asymptotically, but also the asymmetry between the nor thwest and the southeast has indeed been discovered. The mechanisms proposed above could be used to interpret the observation.