标题： II型白光太阳耀斑中的氢发射 显示英文标题

标题： Hydrogen Emission in Type II White-light Solar Flares

摘要： II型WLFs具有弱的巴尔末线发射且没有巴尔末跳跃。 我们进行了一组辐射流体动力学模拟，以了解氢辐射损失如何随电子束参数变化，特别是随低能截止的变化。 我们的结果表明，对于低能束，随着低能截止的增加，过量的耀斑莱曼发射减弱，因为沉积到顶层色球层的能量相比沉积到更深层的能量较低。 一些巴尔末过量发射始终存在，主要由束的直接加热驱动，莱曼连续谱的反向加热贡献较小。 在高低能截止的电子束模型中缺乏莱曼过量发射是II型WLFs显著的光谱特征。 显示英文摘要

摘要： Type II WLFs have weak Balmer line emission and no Balmer jump. We carried out a set of radiative hydrodynamic simulations to understand how the hydrogen radiative losses vary with the electron beam parameters and more specifically with the low energy cutoff. Our results have revealed that for low energy beams, the excess flare Lyman emission diminishes with increasing low energy cutoff as the energy deposited into the top chromosphere is low compared to the energy deposited into the deeper layers. Some Balmer excess emission is always present and is driven primarily by direct heating from the beam with a minor contribution from Lyman continuum backwarming. The absence of Lyman excess emission in electron beam models with high low energy cutoff is a prominent spectral signature of type II WLFs.