Gravitationally coupled scale-free discs
文献类型：期刊论文
| 作者 | Shen, Y; Lou, YQ |
| 刊名 | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
 |
| 出版日期 | 2004-09-01 |
| 卷号 | 353期号:1页码:249-269 |
| 关键词 | waves stars : formation ISM : general galaxies : kinematics and dynamics galaxies : spiral galaxies : structure |
| 英文摘要 | In a composite fluid system of two gravitationally coupled barotropic scale-free discs bearing a rotation curve v proportional to r(-beta) and a power- law surface mass density Sigma(0) proportional to r(-alpha) with alpha = 1 + 2beta, we construct classes of coplanar stationary aligned and logarithmic spiral perturbation configurations in the two discs. Owing to the mutual gravitational interaction, there are two independent classes of perturbation modes, with surface mass density disturbances in the two coupled discs being either in phase or out of phase. We derive analytical criteria for such perturbation modes to exist and show numerical examples. We compute the aligned and spiral perturbation modes systematically to explore the entire parameter regime. For the axisymmetric m = 0 case with radial oscillations, there are two unstable regimes of ring fragmentation and Jeans collapse corresponding to short and long radial wavelengths, respectively. Only within a certain range of the rotation parameter D-s(2) (square of the effective rotational Mach number for the stellar disc) can a composite disc system be stable against all axisymmetric perturbations. Compared with a single-disc system, the coupled two-disc system becomes less stable against such axisymmetric instabilities. Our investigation generalizes the previous work of Syer & Tremaine on the single-disc case and of Lou & Shen on two coupled singular isothermal discs. Non-axisymmetric instabilities are briefly discussed. These stationary models for various large-scale patterns and morphologies may be useful in the context of disc galaxies with bars and spirals or barred spirals. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000223404500025 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/6947]  |
| 专题 | 国家天文台_光学天文研究部 |
| 作者单位 | 1.Tsing Hua Univ, Tsinghua Ctr Astrophys, Dept Phys, Beijing 100084, Peoples R China 2.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China 3.Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA |
| 推荐引用方式 GB/T 7714 | Shen, Y,Lou, YQ. Gravitationally coupled scale-free discs[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2004,353(1):249-269. |
| APA | Shen, Y,&Lou, YQ.(2004).Gravitationally coupled scale-free discs.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,353(1),249-269. |
| MLA | Shen, Y,et al."Gravitationally coupled scale-free discs".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 353.1(2004):249-269. |
入库方式： OAI收割
来源：国家天文台
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