DISK-STABILITY CONSTRAINTS ON THE NUMBER OF ARMS IN SPIRAL GALAXIES
DISK-STABILITY CONSTRAINTS ON THE NUMBER OF ARMS IN SPIRAL GALAXIES
复制标题
螺旋星系中旋臂数量的盘稳定性约束
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
E. D’Onghia
中科院分区：
文献类型：
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作者：
E. D’Onghia
本文提出了一个基于盘稳定性判据的模型，用于确定由Hernquist模型描述的具有指数盘、球和暗晕的一般盘星系的旋臂数目。螺旋结构的多重旋转对称性可以在已知星系的结构特性（如圆速度曲线和盘表面亮度）后进行分析评估。通过改变盘的质量，这些模型的目的是在不同的临界长度尺度参数的磁盘，并导致不同的螺旋形态与以前的模型。以前的研究基于摆动放大和盘稳定性已经被应用到限制盘星系的质光比。这种形式主义提供了一个分析表达式，以估计预期的武器数量的摆动放大，使其应用程序直接大型调查。它可以被用来预测银河系中的臂数作为半径的函数，并限制盘星系的质光比，其中光度和运动学测量是可用的，如在银河系质量巡天。因此，根据正在进行和即将进行的调查，可以推断出盘状星系内部的总质量的晕贡献。
A model based on disk-stability criteria to determine the number of spiral arms of a general disk galaxy with an exponential disk, a bulge and a dark halo described by a Hernquist model is presented. The multifold rotational symmetry of the spiral structure can be evaluated analytically once the structural properties of a galaxy, such as the circular speed curve, and the disk surface brightness, are known. By changing the disk mass, these models are aimed at varying the critical length scale parameter of the disk and lead to a different spiral morphology in agreement with prior models. Previous studies based on the swing amplification and disk stability have been applied to constrain the mass-to-light ratio in disk galaxies. This formalism provides an analytic expression to estimate the number of arms expected by swing amplification making its application straightforward to large surveys. It can be applied to predict the number of arms in the Milky Way as a function of radius and to constrain the mass-to-light ratio in disk galaxies for which photometric and kinematic measurements are available, like in the DiskMass survey. Hence, the halo contribution to the total mass in the inner parts of disk galaxies can be inferred in light of the ongoing and forthcoming surveys.