论文标题
太阳突出中下降的动力及其对加热当地电晕的可能贡献
Dynamics of descending knots in a solar prominence and their possible contributions to the heating of the local corona
论文作者
论文摘要
通常观察到太阳突出的结几乎恒定地降低，但相关的物理机制目前尚不清楚。在这封信中，我们提出了H-Alpha波长中新真空太阳能望远镜（NVST）观察到的突出。在突出性内升起的结似乎优先位于较高的高度，而在整个突出结构中都发现了掉落的结。太阳表面附近的结的降速高于远离太阳能表面的速度。我们注意到，太阳能表面附近的结可能沿着从大气成像组件观察到的一组冠状环。在其他地方，大多数结都被解释为以几乎恒定的速度在更水平的磁场上下降。这种缺乏加速度表明，解放的重力能量可能不会表现为动能的增加。相反，下降的结能够令人兴奋，然后可以在局部电晕内消失，因此结的重力势能可能已转化为热能。因此，假设一个完美的弹性系统，我们估计这些观察到的结的重力能量损失率达到加热整个安静的1/2000所需的1/2000，当考虑到h-alpha观测中消失的结可能进一步下降时增加到1/320。该结果表明，这种机制可能有助于将电晕局部供应到这些突出。
The knots in solar prominences are often observed to fall with nearly constant velocity, but the associated physical mechanism is currently not well understood. In this letter, we presented a prominence observed by New Vacuum Solar Telescope (NVST) in H-alpha wavelength. Knots that rose within the prominence appear to have been preferentially located at higher altitude, whereas those that fell were found throughout the entire prominence structure. The descending speed of the knots near the solar surface was higher than that far away from the solar surface. We noted that the knots near the solar surface may run along a set of coronal loops observed from the Atmospheric Imaging Assembly. Elsewhere, the majority of knots are interpreted to have descended across more horizontal magnetic field with a nearly constant speed. This lack of acceleration indicates that the liberated gravitational potential energy may not manifest as an increase in kinetic energy. Assuming instead that the descending knots were capable of exciting Alfven waves that could then dissipate within the local corona, the gravitational potential energy of the knots may have been converted into thermal energy. Assuming a perfectly elastic system, we therefore estimate that the gravitational energy loss rate of these observed knots amounts to 1/2000 of that required to heat the entire quiet-Sun, increasing to 1/320 when considering possibly further downward motions of the knots having disappeared in the H-alpha observations. This result suggests such a mechanism may contribute to the heating of the corona local to these prominences.
