利用TRACE、STEREO、SOHO/MDI、Hinode/XRT和BBSO的空间和地面观测资料,对2010年2月12日试图从NOAA AR 11045爆发的通量绳和相关的M级太阳耀斑进行了多波长观测。当磁绳从活动区上升时,在其一个支点附近触发了M1.1/2F级耀斑。我们认为,耀斑触发是由于重新连接的上升通量绳与周围的低洼磁回路。磁绳以约90 km/s的速度达到约0.15 Rs的投影高度,而软X射线通量在其上升过程中逐渐增强。磁通绳被上覆场抑制,充满的等离子体向其激活位点以西的负极性场移动。我们发现的第一个观测证据的初始抑制的通量绳由于可见的残留灯丝在色球和日冕的温度,在活动区的同一位置前几天的演变。SOHO/MDI磁象图显示在耀斑开始前约12小时出现了一个双极。出现的负极性向磁绳激活点移动,在光球极性反转线(PIL)附近触发耀斑。负极性区域朝向PIL的运动有助于在耀斑和磁绳激活部位积聚磁能。这项研究提供了一个独特的观测证据,上升的通量绳未能爆发,由于残留的灯丝和覆盖的磁场,以及相关的触发M级耀斑。
英文摘要:
We present the multi-wavelength observations of a flux rope that was trying to erupt from NOAA AR 11045 and the associated M-class solar flare on 12 February 2010 using space and ground based observations from TRACE, STEREO, SOHO/MDI, Hinode/XRT and BBSO. While the flux rope was rising from the active region, an M1.1/2F class flare was triggered nearby one of its footpoints. We suggest that the flare triggering was due to the reconnection of a rising flux rope with the surrounding low-lying magnetic loops. The flux rope reached a projected height of ~0.15 Rs with a speed of ~90 km/s while the soft X-ray flux enhanced gradually during its rise. The flux rope was suppressed by an overlying field and the filled plasma moved towards the negative polarity field to the west of its activation site. We find the first observational evidence of the initial suppression of a flux rope due to a remnant filament visible both at chromospheric and coronal temperatures that evolved couple of days before at the same location in the active region. SOHO/MDI magnetograms show the emergence of a bipole ~12 h prior to the flare initiation. The emerged negative polarity moved towards the flux rope activation site, and flare triggering near the photospheric polarity inversion line (PIL) took place. The motion of the negative polarity region towards PIL helped in the build-up of magnetic energy at the flare and flux rope activation site. This study provides a unique observational evidence of a rising flux rope that failed to erupt due to a remnant filament and overlying magnetic field, as well as associated triggering of an M-class flare.
Flux rope proxies and fan-spine structures in active region NOAA 11897
利用太阳动力学天文台(SDO)和界面区成像光谱仪(IRIS)的高分辨率观测资料,对2013年11月14日至19日期间NOAA AR 11897的通量绳代理进行了统计分析,并显示了该AR中的两个扇脊结构。我们首次在4个不同的位置探测了NOAA 11897的磁绳代理,共30次。这些磁绳代理要么在较低和较高温度的波长跟踪或仅在热通道中检测到。特别是这些弦索代理,没有一个被观测到爆发,而是逐渐消失。除了这些磁绳代理,我们首先检测到一个次级扇脊结构。它被圆顶形的磁场覆盖,属于一个更大的扇脊拓扑结构。这些新的观测结果表明,在AR中可以存在大量的磁通绳,AR磁位形的复杂性远远超出了我们的想象。
Large-scale solar eruptions are believed to have a magnetic flux rope as the core structure. However, it remains elusive as to how the flux rope builds up and what triggers its eruption. Recent observations found that a prominence erupted following multiple episodes of "flux feeding". During each episode, a chromospheric fibril rose and merged with the prominence lying above. In this letter, we carried out 2.5-dimensional magnetohydrodynamic (MHD) numerical simulations to investigate whether the flux-feeding mechanism can explain such an eruption. The simulations demonstrate that the discrete …
Whether a solar eruption is successful or failed depends on the competition between different components of the Lorentz force exerting on the flux rope that drives the eruption. The present models only consider the strapping force generated by the background magnetic field perpendicular to the flux rope and the tension force generated by the field along the flux rope. Using the observed magnetic field on the photosphere as a time-matching bottom boundary, we perform a data-driven magnetohydrodynamic simulation for the 30 January 2015 confined eruption and successfully reproduce the observed so…
We present the study of three homologous solar eruptions from NOAA active region (AR) 11429 over four days. This large and complex AR divided into two relatively simple sub-regions: northeast (NE) and southwest (SW). Recurrent eruptions occurred from the SW sub-region over different evolutionary phases, which provided a unique opportunity to isolate the physical processes responsible for solar eruptions. Persistent shearing and convergence of opposite magnetic polarities led to continuous flux cancellation along the SW polarity inversion line (PIL). A filament persistently lying along the SW-P…
Coronal magnetic flux ropes are generally considered to be the core structure of large-scale solar eruptions. Recent observations found that solar eruptions could be initiated by a sequence of "flux feeding," during which chromospheric fibrils rise upward from below, and merge with a pre-existing prominence. Further theoretical study has confirmed that the flux feeding mechanism is efficient in causing the eruption of flux ropes that are wrapped by bald patch separatrix surfaces. But it is unclear how flux feeding influences coronal flux ropes that are wrapped by hyperbolic flux tubes (HFT), a…
It is widely believed that magnetic flux ropes are the key structure of solar eruptions; however, their observable counterparts are not clear yet. We study a flare associated with flux rope eruption in a comprehensive radiative magnetohydrodynamic simulation of flare-productive active regions, especially focusing on the thermodynamic properties of the plasma involved in the eruption and their relation to the magnetic flux rope. The pre-existing flux rope, which carries cold and dense plasma, rises quasi-statically before the eruption onsets. During this stage, the flux rope does not show obvio…
We present a multiwavelength analysis of two homologous, short lived, impulsive flares of GOES class M1.4 and M7.3, that occurred from a very localized mini-sigmoid region within the active region NOAA 12673 on 2017 September 7. Both flares were associated with initial jet-like plasma ejection which for a brief amount of time moved toward east in a collimated manner before drastically changing direction toward southwest. Non-linear force-free field extrapolation reveals the presence of a compact double-decker flux rope configuration in the mini-sigmoid region prior to the flares. A set of open…
Magnetohydrodynamics simulation of active region NOAA 11515 is performed to examine the initiation of the M5.6 flaring event that starts around 10:43 UT on 2012 July 2. The simulation is conducted using an extrapolated non-force-free magnetic field generated from the photospheric vector magnetogram of the active region as the initial magnetic field. The magnetic field shows the presence of a three-dimensional (3D) magnetic null with the corresponding dome overlying a filament and a low-lying magnetic flux rope, observed in 304~Å~ and 131~Å~ respectively. The simulated dynamics, triggered by th…
Filament Eruption in NOAA 11093 Leading to a Two-Ribbon M1 Class Flare and CME
利用SDO、STEREO、RHESSI和GONG H $α$网络望远镜获得的数据,对2010年8月7日发生在活动区(AR)NOAA 11093的一次喷发事件进行了多波长分析。根据这些观测结果,我们推断,位于极性反转线(PIL)上的反S形暗条的向上缓慢上升运动导致了双带耀斑之后的CME。上覆磁力线穿过灯丝与旁瓣磁力线的相互作用,相关的EUV增亮,以及灯丝周围的通量出现/取消是导致其不稳定和爆发的过程的观测特征。此外,暗条/磁绳的上升运动轮廓与耀斑特征,即,重连率和HXR发射曲线。通量绳在耀斑的峰值阶段加速到最大速度作为CME,然后减速到平均速度为590 km $^{-1}$。我们认为,所观察到的出现/取消附近的灯丝的磁通量导致它上升,导致在系绳切割和重新连接发生在灯丝下,在协议与系绳切割模型。相应的增加/减少,发现在后高峰阶段的爆发的光球通量的正/负提供了明确的证据,重新连接的系绳切割的结果。
We investigate the onsets of three consecutive coronal mass ejection (CME) eruptions in 12 hours from a large bipolar active region (AR) observed by SDO, STEREO, RHESSI, and GOES. Evidently, the AR initially had a triple-decker configuration: three flux ropes in a vertical stack above the polarity inversion line (PIL). Upon being bumped by a confined eruption of the middle flux rope, the top flux rope erupts to make the first CME and its accompanying AR-spanning flare arcade rooted in a far-apart pair of flare ribbons. The second CME is made by eruption of the previously-arrested middle flux r…
Interpreting Eruptive Behavior in NOAA AR 11158 via the Region's Magnetic Energy and Relative Helicity Budgets
在以前的工作中,我们介绍了一个非线性无力的方法,自洽计算的自由磁能和相对磁螺旋度在太阳活动区(AR)的瞬时预算。计算是方便和实用的,每次计算仅使用单个矢量磁图。我们将这种方法应用于600个高节奏的矢量磁图的爆发NOAA AR 11158收购的日震和磁成像仪船上的太阳动力学天文台在五天的观测间隔的时间序列。除了广泛测试我们的方法,我们用它来解释AR的动态演化,包括爆发。我们发现,AR建立了自由磁能和相对磁螺旋度的大预算,足以为更多的喷发提供动力,而不是在感兴趣的区间内。对于每一个这些主要的爆发,我们发现喷发相关的减少和随后的自由能和螺旋度预算与观测到的喷发(耀斑和日冕物质抛射[CME])的大小一致。此外,我们发现(1)AR中的演化与最近提出的(自由)能量一致-(2)爆发相关的衰减发生在耀斑和预计的日冕物质抛射发射时间之前{ \it},表明日冕物质抛射的前身先于耀斑,(3)自由能和相对螺旋度的自项很可能来源于各自的互项,遵循最有可能源于磁重联的渐进的相互-自我转换模式。这导致了非理想的形成越来越螺旋状的喷发前结构,并激发了进一步的研究与磁螺旋牢固地放置在喷发干部的太阳喷发的触发。
Formation and Eruption of a Vortex-driven Magnetic Flux Rope in the Simulated Quiet Sun
School of Astronomy and Space Science, Nanjing University(南京大学天文与空间科学学院);Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education(南京大学现代天文与天体物理教育部重点实验室)
We present evidence that a magnetic flux rope was formed before a coronal mass ejection (CME) and its associated long-duration flare during a pair of preceding confined eruptions and associated impulsive flares in a compound event in NOAA Active Region 12371. Extreme-ultraviolet images and the extrapolated nonlinear force-free field show that the first two, impulsive flares, SOL2015-06-21T01:42, result from the confined eruption of highly sheared low-lying flux, presumably a seed flux rope. The eruption spawns a vertical current sheet, where magnetic reconnection creates flare ribbons and loop…
In this paper, we present multiwavelength observations of the triggering of a failed-eruptive M-class flare from the active region NOAA 11302, and investigate the possible reasons for the associated failed eruption. Photospheric observations and Non-Linear Force Free Field extrapolated coronal magnetic field revealed that the flaring region had a complex quadrupolar configuration with a pre-existing coronal null point situated above the core field. Prior to the onset of the M-class flare, we observed multiple periods of small-scale flux enhancements in GOES and RHESSI soft X-ray observations, …
We investigate the formation times of eruptive magnetic flux ropes relative to the onset of solar eruptions, which is important for constraining models of coronal mass ejection (CME) initiation. We inspected uninterrupted sequences of 131 Å images that spanned more than eight hours and were obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) to identify the formation times of hot flux ropes that erupted in CMEs from locations close to the limb. The appearance of the flux ropes as well as their evolution toward eruptions were determined using morphol…
Coronal mass ejections (CMEs) are large-scale explosions of the coronal magnetic field. It is believed that magnetic reconnection significantly builds up the core structure of CMEs, a magnetic flux rope, during the eruption. However, the quantitative evolution of the flux rope, particularly its toroidal flux, is still unclear. In this paper, we study the evolution of the toroidal flux of the CME flux rope for four events. The toroidal flux is estimated as the magnetic flux in the footpoint region of the flux rope, which is identified by a method that simultaneously takes the coronal dimming an…
Rapid buildup of a magnetic flux rope during a confined X2.2 class flare in NOAA AR 12673
磁通量绳(MFR)被认为是太阳爆发的核心结构,然而,其形成仍然存在激烈的争论。在这里,我们报告了2017年9月6日发生在NOAA AR 12673的X2.2级耀斑期间MFR系统的快速积累过程,三小时后,该结构爆发为主要的日冕物质抛射(CME),伴随着X9.3级耀斑。对于X2.2耀斑,我们没有发现EUV调光,分离的耀斑带,或明确的CME签名,这表明一个局限的耀斑。对于X9.3耀斑,大规模的变暗、耀斑带的分离和CME表明它是爆发性的。通过非线性无力场(NLFFF)的时间序列外推,我们发现:直到爆发耀斑,MFR系统位于AR。在受限耀斑期间,MFR系统的轴向通量和磁螺旋度下限分别显著增强了约86%和260%,尽管平均扭曲数几乎没有变化。在爆发耀斑期间,这三个参数都显著降低。结果表明,建立和释放的MFR系统在封闭和爆发耀斑,分别。前者可以通过扩口重连来实现。我们还计算了耀斑前主极性反转线(PIL)以上衰变指数的分布,没有发现显着差异。这表明磁共振系统的磁通量和螺旋度的增加可能在促进其最终喷发中起作用。
Compound eruptions represent that multiple closely spaced magnetic structures erupt consecutively within a short interval, and then lead to a single flare and a single CME. However, it is still subtle for the links between multiple eruptions and the associated single flare or/and single CME. In this Letter, we report the compound eruptions of twin close flux ropes (FR1 and FR2) within a few minutes that resulted in a flare with a single soft X-ray peak and a CME with two cores. The successive groups of expanding loops and double peaks of intensity flux in AIA cool wavelengths indicate two epis…
Identification of Pre-flare Processes and Their Possible Role in Driving a Large-scale Flux Rope Eruption with Complex M-class Flare in the Active Region NOAA 12371
We report a decaying kink oscillation of a flux rope during a confined eruptive flare, observed off the solar limb by SDO/AIA, that lacked a detectable white-light coronal mass ejection. The erupting flux rope underwent kinking, rotation, and apparent leg-leg interaction during the event. The oscillations were observed simultaneously in multiple AIA channels at 304, 171, and 193 Å, indicating that multithermal plasma was entrained in the rope. After reaching the overlying loops in the active region, the flux rope exhibited large-amplitude, decaying kink oscillations with an apparent initial am…
A magnetic flux rope (FR), hosting hot plasma, is thought to be central to the physics of coronal mass ejection. Such FRs are widely observed with passbands of the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO), that are sensitive to emission from the hot plasma around 10 MK. In contrast, observations of warmer (around 1 MK) counterparts of FRs are sparse. In this study, we report the failed eruption of a multi-thermal FR, hosting both hot and warm plasma. On 2015 May 1, a hot channel appeared in the AIA high temperature passbands out of the southeastern solar …
Interplanetary Coronal Mass Ejections (ICMEs) originate from the eruption of complex magnetic structures occurring in our star's atmosphere. Determining the general properties of ICMEs and the physical processes at the heart of their interactions with the solar wind is a hard task, in particular using only unidimensional in situ profiles. Thus, these phenomena are still not well understood. In this study we simulate the propagation of a set of flux ropes in order to understand some of the physical processes occurring during the propagation of an ICME such as their growth or their rotation. We …