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arXiv 1002.1245astro-ph.GAastro-ph.CO
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直接测量棒料速度

Direct measurements of bar pattern speeds

E. M. Corsini

摘要:

棒星系的动力学取决于它的棒的角速度或模式速度。实际上,它与杆的静止坐标系中重力和离心力相互抵消的共转位置有关。测量条型速度的唯一直接方法是Tüssee-Weinberg技术。这种方法最适合于在没有显著恒星形成和斑片状尘埃遮蔽的情况下分析恒星成分的分布和运动学。因此,它主要用于早期型棒星系。讨论了直接测量棒材速度不确定度的主要来源。有人试图通过将Tubee-Weinberg方法的应用扩展到气体组分来克服当前直接测量样品的选择偏差。此外,还有各种基于气体分布和运动学分析的间接方法。它们主要用于测量晚型棒星系中的条斑速度。几乎所有用直接和间接方法测量的棒都在它们的共转半径附近结束,即,它们尽可能快速地旋转。

英文摘要:

The dynamics of a barred galaxy depends on the angular velocity or pattern speed of its bar. Indeed, it is related to the location of corotation where gravitational and centrifugal forces cancel out in the rest frame of the bar. The only direct method for measuring the bar pattern speed is the Tremaine-Weinberg technique. This method is best suited to the analysis of the distribution and kinematics of the stellar component in absence of significant star formation and patchy dust obscuration. Therefore, it has been mostly used for early-type barred galaxies. The main sources of uncertainties on the directly-measured bar pattern speeds are discussed. There are attempts to overcome the selection bias of the current sample of direct measurements by extending the application of the Tremaine-Weinberg method to the gaseous component. Furthermore, there is a variety of indirect methods which are based on the analysis of the gas distribution and kinematics. They have been largely used to measure the bar pattern speed in late-type barred galaxies. Nearly all the bars measured with direct and indirect methods end close to their corotation radius, i.e., they are as rapidly rotating as they can be.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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