Centrifugally driven winds from contracting molecular disks
Centrifugally driven winds from contracting molecular disks
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DOI：
10.1086/161481
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发表时间：
1983-11
期刊：
影响因子：
--
通讯作者：
R. Pudritz;C. Norman
中科院分区：
文献类型：
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作者：
R. Pudritz;C. Norman
我们认为，与年轻恒星天体相关的致密分子云中的双极外流是稳定的、离心驱动的、磁流体风，它产生于嵌入红外源的分子盘（尺度≤ 10/sup 16/ cm）。质量约为100 M/亚太阳/和转速约为10/sup 6/ cm s/sup-1/的盘提供了10/sup 47/尔格的储备，这可以为观测到的最具能量的外流提供动力。加速到超音速是由嵌入在圆盘中的磁场（平行的旋转轴和磁轴）完成的，并向外延伸到风区之外加入银河场。风把圆盘的角动量和能量带到很远的地方。我们的分析对待的问题，磁制动和能量传输的部分电离（两种流体）风。控制流动的基本参数是耦合参数。beta.. = T/sub n/-i/T/sub n/，特征中性离子碰撞时间与流动时间之比。给出了角动量和能量输运的一般分析，并沿着通量管在强耦合（... beta.. <<1）极限。离心驱动的风形成时，嵌入的原恒星开始膨胀的磁盘核心区域。一个圆盘外壳在风基地形成的压力，调整到风的要求。包封加热可通过致密芯（其具有约10/sup-3/高斯的场）的磁通量损失来维持，对于扁平盘，致密芯优选沿着旋转轴。导出了盘芯表面的场结构。观测的影响进行了讨论，特别是，我们强调，这样的分子盘双配置文件应进行观察。«少
We suggest that bipolar outflows in dense molecular clouds associated with young stellar objects are steady, centrifugally driven, hydromagnetic winds that arise from molecular disks (on scales < or =10/sup 16/ cm) in which the infrared source(s) embedded. A disk of mass approx.100 M/sub sun/ and rotational speed of approx.10/sup 6/ cm s/sup -1/ provides a resevoir of 10/sup 47/ ergs, which could power the most energetic outflows observed. Acceleration to supersonic speeds is accomplished by the magnetic field embedded in the disk (paralllel rotational and magnetic axes) and extending outward beyond the wind region to join the galactic field. The wind carries angular momentum and energy from the disk out to large distances. Our analysis treats the problem of magnetic braking and energy transport in a partially ionized (two-fluid) wind. The basic parameter which is shown to govern the flow is the coupling parameter ..beta.. = T/sub n/-i/T/sub n/, the ratio of the characteristic neutral-ion collision time to flow time. A general analysis of angular momentum and energy transport is given, and the wind equation is solved along flux tubes in the strongly coupled (..beta..<<1) limit. The centrifugally driven wind forms when an embedded protostar begins to ionize themore » disk core region. A disk envelope forms at the wind base at a pressure which adjusts to the wind requirements. Envelope heating may be maintained by magnetic flux loss from the dense core (which has a field approx.10/sup -3/ gauss) that is preferentially along the rotation axis for flattened disks. The structure of the field at the disk core surface is derived. The observational implications are discussed; in particular, we emphasize that such molecular disks with double profiles should be observed.« less