Abstract

Examination results for specific features of variation of line-of-sight plasma velocities in different photosphere layers of the NOAA 11024 active region (AR) under the influence of two evolving Ellerman bombs (EB-1 and EB-2) are presented. Spectroscopic data with high spatial and temporal resolution were obtained with the French–Italian THEMIS solar telescope on July 4, 2009. The observation time was 20 min. The AR was undergoing a sharp increase in activity on the day of observations, and the EBs evolved in the region of one of the three magnetic fluxes that were emerging at the time. The brightness of EB-1 decreased during observations, while EB-2 got brighter. The λ ≈ 630 nm spectral region, which includes Fraunhofer lines forming within a wide range of photospheric heights (neutral iron lines Fe I λ 630.15, 630.25, and 630.35 nm and titanium line Ti I λ 630.38 nm), was used. Changes in the velocity and direction of motion of matter in the region of Ellerman bombs and in their immediate vicinity at different photosphere levels and at different stages of EB evolution were determined and analyzed. It was found that upflows were predominant at all levels of the AR photosphere. At the same time, line-of-sight velocities V_los and the amplitude of their oscillations decreased considerably in the region of EBs. Apparently, downward matter flows reduced the velocity of upward plasma motion. This suggests that small-scale downward flows induced by magnetic reconnections were superimposed onto the large-scale upward motion of plasma of the new magnetic flux. The profile shape of photospheric lines reinforces this conclusion. The profiles of strong lines had a red asymmetry. The matter velocity determined based on the shift of a prominent component in the red wing of the Fe I λ 630.35 nm line profiles was as high as 2 km/s. Such a V_los distribution in the EB regions indicates that they consisted of several jets moving with different velocities in different directions. The line-of-sight velocity in the central part of EB-1 and EB-2 varied from –1 to 0 km/s and from –1 to 0.2 km/s in the upper photospheric layer and from –1.6 to –0.2 km/s and from –1.1 to 0.25 km/s in the lower layer of the photosphere, respectively. V_los variations in the vicinity of these Ellerman bombs were oscillatory, and the interval between oscillations was ~5 min. The pattern of quasiperiodic V_los oscillations was disturbed in the EB regions: they often occurred in antiphase. It may be concluded that the excitation caused by a pulsed energy release as a result of successive magnetic reconnections associated with the emergence of the new magnetic flux propagated from the EB-1 site along a magnetic loop and triggered the formation of EB-2, and the Ellerman bombs then evolved as a physically connected pair. The studied features of the line-of-sight velocity variation of chromospheric and photospheric matter indicate that during the evolved of EBs differently directed motions of matter there was: it moved upward in the lower chromospheric layer, while downward flows reduced the velocity of ascending plasma at the photospheric level. Magnetic reconnections occurring in the layer between the upper photosphere and the lower chromosphere, where the core of the H_α line was formed, could induce such a velocity distribution.

中文翻译：

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活动区域内有两个Ellerman炸弹的光球物质运动

摘要

给出了在两种进化的埃勒曼炸弹（EB-1和EB-2）的影响下，NOAA 11024有源区（AR）不同光球层视线等离子体速度变化的特定特征的检验结果。2009年7月4日，使用法国-意大利THEMIS太阳望远镜获得了具有高时空分辨率的光谱数据。观测时间为20分钟。在观察之日，AR的活动急剧增加，而EB在当时出现的三种磁通量之一的区域内演化。观察期间EB-1的亮度降低，而EB-2的亮度更高。λ≈630 nm光谱区，其中包括在很宽的光球高度范围内形成的弗劳恩霍夫线（中性铁线Fe Iλ630.15、630.25和630。使用35 nm和钛线Ti Iλ630.38 nm）。确定并分析了Ellerman炸弹区域及其附近地区在不同光圈水平和EB演化的不同阶段物质运动的速度和方向的变化。发现在AR光球的所有水平上，上流都是主要的。同时，视线速度在电子束区域，V _los及其振荡幅度大大降低。显然，物质的向下流动降低了等离子体向上运动的速度。这表明由磁重连引起的小规模向下流动叠加在新磁通量的等离子体的大范围向上运动上。光球线的轮廓形状加强了这一结论。强线的轮廓具有红色不对称性。根据Fe Iλ630.35 nm线轮廓的红色机翼中显着成分的移动确定的物质速度高达2 km / s。这样的V_洛杉矶EB区域的分布表明它们由几个以不同速度沿不同方向运动的射流组成。EB-1和EB-2中部的视线速度从–1到0 km / s，在上层光球层从–1到0.2 km / s，从–1.6到–0.2 km / s，并且在光球的下层分别从–1.1到0.25 km / s。这些Ellerman炸弹附近的V _los变化是振荡的，振荡之间的间隔约为5分钟。准周期V _los的模式振荡在EB区受到干扰：它们通常发生在反相状态。可以得出这样的结论：由脉冲能量释放引起的激励是由于与从EB-1部位沿磁环传播并触发EB-2的新磁通的出现相关的连续磁重新连接而引起的；然后，埃勒曼炸弹演变为物理连接的一对。色球层和光球层物质视线速度变化的研究特征表明，在电子束的演化过程中，物质的定向运动不同：它在较低的色球层中向上移动，而向下的流动则降低了上升等离子体的速度。在光球层。在上部光圈和下部色圈之间的层中发生了磁重联，形成了_α线，可能引起这种速度分布。