Effects of Rotation on the Spatial Structure of Wolf-Rayet Winds

自转对沃尔夫拉叶风空间结构的影响

• 批准号: 9417186
• 负责人: Joseph Cassinelli
• 金额: $ 18.6万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-01-15 至 1999-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9417186&HistoricalAwards=false
• 关键词: Effects; Rotation; Spatial; Structure; Wolf

Cassineli 9417186 Wolf-Rayet (WR) stars have winds with very large mass-loss rates and fast terminal speeds. The resultant wind momentum flux greatly exceeds that in the emergent radiation field. In contrast with the winds of O stars, the WR winds appear to accelerate rather slowly so that moderate stellar rotation can lead to a significant enhancement of the density in the equatorial region of the stars. This research is to develop two-dimensional models of the winds and to investigate the consequences of the structure for the observations of WR stars using the "Wind Compression Zone" model. It is based on the "Wind Compression Disk" model, which was developed for rapidly rotating Be stars. For stars rotating at about 10% to 20% critical, the wind compression may explain a number of puzzling observational properties of WR stars, such as why only some WR stars show polarization and why WR stars with compact companions can have strong X-ray emission. In addition, we will study the Luminous Blue Variables (LBVs) using our 2-D WCZ model. These objects are thought to be a precursor stage to the WR phase. LBVs are observed to have slow winds, and some appear to have axisymmetric structure (e.g. AG Carinae), which indicates that these stars are also good candidates for the application of our rotating wind model. There is also evidence of non-thermal radio emission from WR stars and that the winds might be source of high energy particle production. Because of these observations magnetic fields will also be included in the WCZ picture. This will allow us to re-interpret the observational evidence, and also allow us to investigate the consequences of the fields on the wind dynamics. ***

卡西内利 9417186 沃尔夫拉叶 (WR) 恒星的风具有非常大的质量损失率和快速的终端速度。由此产生的风动量通量大大超过了出射辐射场中的风动量通量。 与 O 星的风相比，WR 风的加速速度相当缓慢，因此适度的恒星自转可以导致恒星赤道区域的密度显着增强。 这项研究旨在开发风的二维模型，并利用“风压缩区”模型研究该结构对 WR 恒星观测的影响。 它基于“风压缩盘”模型，该模型是为快速旋转的 Be 恒星而开发的。 对于以大约 10% 到 20% 临界旋转的恒星，风压缩可以解释 WR 恒星的许多令人费解的观测特性，例如为什么只有一些 WR 恒星表现出偏振以及为什么具有致密伴星的 WR 恒星可以具有强烈的 X 射线发射。 此外，我们将使用我们的 2-D WCZ 模型研究发光蓝色变量 (LBV)。 这些物体被认为是 WR 阶段的前兆阶段。 LBV被观察到具有缓慢的风，并且有些似乎具有轴对称结构（例如AG Carinae），这表明这些恒星也是应用我们的旋转风模型的良好候选者。 还有证据表明 WR 恒星的非热射电发射，并且风可能是高能粒子产生的来源。 由于这些观测结果，磁场也将包含在 WCZ 图片中。 这将使我们能够重新解释观测证据，也使我们能够调查场对风动力学的影响。 ***