早期太阳的磁-旋转输运
摘要
角动量输运必须在太阳的辐射层中发生，以解释其当前的刚体旋转。我们对早期太阳辐射层相对于扩散旋转不稳定性的稳定性进行了调查，探讨了各种合理的过去配置。我们发现，尽管仅存在较弱的径向微分旋转，较快旋转的早期太阳仍然容易发生旋转不稳定，而当前的太阳则不然。通过动力学与扩散时间尺度之间的近似平衡来确定稳定域，从而可推广至其他恒星情形。 Depending on the strength and geometry of the weak magnetic field present, the fastest growing unstable mode can be hydrodynamic or magneto-hydrodynamic (MHD) in nature. Our results suggest that diffusive MHD modes may be more efficient at transporting angular momentum than their hydrodynamic (``Goldreich-Schubert-Fricke'') counterparts because the minimum spatial scale required for magnetic tension to be destabilizing limits the otherwise very small scales favored by double-diffusive instabilities. Diffusive magneto-rotational instabilities are thus attractive candidates for angular momentum transport in the early Sun's radiative zone.
引用
@article{arxiv.astro-ph/0606358,
title = {Magneto-Rotational Transport in the Early Sun},
author = {Kristen Menou and Joel LeMer},
journal= {arXiv preprint arXiv:astro-ph/0606358},
year = {2008}
}
备注
23 pages, 4 figures, accepted for publication in ApJ