Effects of Rotation on the Spatial Structure of Wolf-Rayet Winds
Effects of Rotation on the Spatial Structure of Wolf-Rayet Winds
批准号:
9417186
负责人:
Joseph Cassinelli
金额:
$18.6万
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
项目状态:
已结题
起止时间:
1995-01-15 至 1999-12-31
中文摘要
Cassineli 9417186 Wolf-Rayet(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。与O星的风相比,WR风的加速速度似乎相当慢,因此适度的恒星自转可以导致恒星赤道区密度的显著增加。这项研究是为了建立风的二维模型,并利用“风压缩带”模型研究结构对WR恒星观测的影响。它是以“风压缩盘”模型为基础的,该模型是为快速旋转的Be恒星而开发的。对于大约10%到20%临界自转的恒星,风压缩可能解释了WR星的一些令人费解的观测特性,例如为什么只有一些WR星表现出偏振,为什么有致密伴星的WR星可以有很强的X射线发射。此外,我们将使用我们的2-D WCZ模型来研究发光蓝变量(LBV)。这些天体被认为是WR相的前驱阶段。观测到的LBV具有缓慢的风速,其中一些似乎具有轴对称结构(例如AG船底座),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。也有证据表明来自WR恒星的非热射电波辐射,风可能是高能量粒子产生的来源。由于这些观测,磁场也将被包括在WCZ图像中。这将使我们能够重新解释观测证据,并使我们能够调查这些场对风动力学的影响。***
英文摘要
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. ***
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会议论文
Effects of Rotation and Magnetic Fields on the Winds from Early Type Stars
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批准号:9115375
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项目类别:Continuing Grant
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资助金额:$18.6万
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财政年份:1992
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负责人:Joseph Cassinelli
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依托单位:
ASP Scientific Symposium - Massive Stars: Their Lives in the Interstellar Matter, to be held at the University of Wisconsin on June 23-25, 1992.
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批准号:9123168
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项目类别:Standard Grant
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资助金额:$0.64万
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财政年份:1992
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负责人:Joseph Cassinelli
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依托单位:
The Structure of the Outer Atmospheres of Early-Type Stars as Influenced by Magnetic Fields
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批准号:8419907
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项目类别:Continuing Grant
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资助金额:$14.27万
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财政年份:1985
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负责人:Joseph Cassinelli
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依托单位:
Studies of the Nature and Formation of a Possible Supermassive Star in the Large Magellanic Cloud
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批准号:8301750
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项目类别:Standard Grant
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资助金额:$5.58万
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财政年份:1983
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负责人:Joseph Cassinelli
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依托单位:
Studies of the Central Object of the 30 Doradus Nebula
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批准号:8118814
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项目类别:Standard Grant
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资助金额:$4.5万
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财政年份:1982
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负责人:Joseph Cassinelli
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依托单位:
Studies of Expanding Atmospheres of Luminous Stars
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批准号:7912141
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项目类别:Standard Grant
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资助金额:$6.17万
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财政年份:1979
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负责人:Joseph Cassinelli
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依托单位:
Studies of Extended and Expanding Stellar Atmospheres
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批准号:7615448
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项目类别:Continuing Grant
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资助金额:$7.96万
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财政年份:1976
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负责人:Joseph Cassinelli
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依托单位:
海外基金