太阳X射线爆发与甚低频传播相位异常关系的研究

本文对Omega系统H台,E台甚低频信号的相位实测资料及太阳耀斑软X射线资料进行了分析及研究,分析表明甚低频相位异常与太阳耀斑软X射线之间存在着极好的相关性。对白天相位变化值随太阳天顶角位置的变化效应进行修正得到修正公式,并对太阳天顶角、太阳耀斑事件效应的影响进行归算后,可得出两者之间的定量关系,经修正和归算后的相位变化量推断太阳耀斑X射线辐射流量密度值。反之,亦可由后考一太阳X射线爆发峰值流量密度值来预报相位变化量及电离层等效反射高度的变化。     

AR5395活动区演化中耀斑发生的周期性(摘要)

自1974年有连续的太阳软X射线辐射观测以来,AR5395是X射线耀斑产率最高的活动区,过日面13天内共产生106个X射线耀斑,其中X级耀斑就有11个,平均一天发生一次X级耀斑。用S.G.D.资料,对X射线峰值流量Fx,X射线耀斑出现率     

修正的Neupert效应

Neupert效应的定性描述是耀斑中脉冲分量(硬X射线、微波暴)与渐变分量(软X射线发射)之间存在的因果关系,即耀斑最初的能量是以加速粒子的形式释放,加速的电子在大气传输过程中产生非热硬X射线轫致辐射,并加热大气,耀斑软X射线发射是高能粒子注入大气的响应.根据经典Neupert效应的定量描述,硬X射线发射(表征非热电子注入)结束时软X射线应该立刻达到极大,但以往的观测发现一些耀斑软X射线峰值时间(t2)明显晚于硬X射线结束时间(t1)(τ=t2–t1,τ 0),热与非热辐射之间存在明显的偏离经典Neupert效应的情况.为了研究偏离经典Neupert效应的事件,在2002—2015年间的RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager)和GOES (Geostationary Operational Environmental Satellites)耀斑列表中,按照在25–50 keV范围内光变较简单、软X射线有对应发射峰等判据,共选择276个耀斑样本,统计了这些耀斑的τ分布、环长d (用双足点源之间的距离来表征)与τ的关系.结果显示:(1)有227个耀斑τ 0,即有约82%的耀斑偏离经典Neupert效应;(2)τ与d之间存在一定的线性相关,即环越长,软X射线极大的时间越延后;(3)似乎存在一个临界距离,当环长小于临界距离时,经典Neupert效应成立.这些结果印证了修正Neupert效应的必要性,并对其物理意义进行了讨论.     

一类X射线发射度在脉冲相具有显著指数增长特征的太阳耀斑

太阳耀斑脉冲相的X射线光变曲线的复杂性表明此阶段有多种物理过程参与其中.基于某些显著的观测特征对耀斑分类可以用来探索这些特征的物理起源.对GOES (Geostationary Operational Environmental Satellite)卫星观测数据的分析表明有一类X射线发射度在脉冲相呈显著指数增长的耀斑.指数增长阶段的平均温度为正态分布.在此温度分布1σ之内的大多数耀斑属于B级或C级耀斑,其GOES低通道流量的峰值分布为对数正态分布.指数增长相的增长率和持续时间也遵循对数正态分布.持续时间分布范围大概为几十秒到几千秒.正如所预期的,增长时标同软X射线的衰减时标具有相关性.此外,指数增长相的增长率与持续时间呈强烈的反相关,而且随增长率的增大,对应的平均温度也有缓慢增大的趋势.     

太阳热X射线耀斑区特征参量的确定

本报告介绍了利用观测的软 X 射线流量决定太阳耀斑区特征参量的一种方法。并对太阳耀斑区模型作了初步介绍。     

太阳质子辐射和软X射线耀斑与射电爆发间的相关研究

统计分析了太阳质子事件与微波爆发和软Ｘ射线（ＳＸＲ）耀斑间的关系．结果表明：质子事件的峰值流量与微波爆发和ＳＸＲ耀斑的峰值流量、能通量间呈正的对数线性相关,相关系数０．７—０．８．根据这一统计结果和观测的微波爆发、ＳＸＲ耀斑的有关物理量,可以估算伴随的质子事件峰值流量．太阳质子辐射、ＳＸＲ耀斑和微波爆发三者间的共生关系,可以用磁环中耀斑产生的磁流体动力学过程来解释．大约３３％的质子事件没有对应的Ⅱ型爆发,这表明高能质子的加速有随机ＭＨＤ湍流加速（有Ⅱ型暴）和低频快磁声波湍动加速（无Ⅱ型暴,但有γ射线耀斑）２种不同的加速机制     

紫金山天文台太阳射电频谱仪定标

定标是射电天文观测中基础而重要的工作.定标工作可以得到太阳观测中的一个重要物理量:太阳射电辐射流量,可以扣除射电频谱仪的通道不均匀性,清晰显示射电频谱特征.结合紫金山天文台射电频谱仪的观测数据,详细介绍了定标的基本方法,分析了定标常数的变化情况,最后给出了定标结果,并与野边山射电偏振计以及RHESSI(The Reuven Ramaty High Energy Solar Spectroscopic Imager)卫星硬X射线波段的几个太阳耀斑的观测结果进行了比较,结果符合耀斑的光变特征.其中对一个耀斑脉冲相硬X射线流量和微波光变的相关性的分析表明这些观测可以用来研究有关的辐射机制以及相应的能量释放和粒子加速过程.     

ASO-S/HXI太阳指向镜算法研究

硬X射线成像是研究太阳耀斑等爆发现象的重要手段.由于采用调制成像而非直接成像的原因, X射线图像在日面上的位置需要借助太阳指向镜提供的仪器指向的日面坐标来确定.因此,指向信息对于耀斑定位实现多波段研究,理解太阳耀斑的物理过程具有重要的科学意义.在此对两种太阳指向镜指向信息的获取算法进行了测试.结合太阳指向镜的设计方案,首先利用SDO (Solar Dynamics Observatory)/AIA (Atmospheric Imaging Assembly) 4500?的数据产生测试图像,其次对其进行二值化处理,分别提取日面轮廓和4个边角指定区域面积;最后分别利用最小二乘法和四象限法对太阳中心坐标进行反演.初步结果显示最小二乘法受随机噪声影响小,定位精度相对稳定约为0.25′′,并可提供四象限法解算的初值;后者的精度可以优于0.14′′,但受随机噪声影响较大.两种算法的精度都显著优于硬X射线成像仪(Hard X-ray Imager, HXI)太阳指向镜的设计要求,可为指向数据在将来科学分析中的实际应用提供参考.     

2015年11月4日太阳射电爆发干扰导航信号事件中的X射线先兆分析

太阳射电爆发是无线通讯特别是卫星导航通讯的潜在影响因素之一。2015年11月4日的太阳射电爆发事件在1 415 MHz点频的流量达到了峰值5 800 SFU(Solar Flux Unit,太阳射电流量单位,1 SFU=10~(-22) W/(m~2·Hz)),位于日下点的欧洲全球定位系统(Global Positioning System, GPS)和瑞典的航空导航系统均受到了影响。分析了此次事件产生源活动区的X射线流量变化与射电流量变化之间的时间关系;通过比对,X射线的流量抬升时间较射电阈值有30 min的提前量。随后讨论了提前量之间的物理背景,即软硬X射线分别对应热电子和非热电子辐射,而非热电子是产生能够造成此类空间天气事件射电爆发的物理条件,X射线由软转硬的过程中流量的抬升变化,为进一步防控这类空间天气事件提供了一种有效的手段。     

ASO-S卫星HXI量能器探测单元的标定

先进天基太阳天文台卫星(Advanced Space-based Solar Observatory, ASO-S)是中国科学院第2批空间科学先导专项之一,其主要目标是同时观测太阳磁场、耀斑和日冕物质抛射,并对3者之间的相互关系和内在联系进行研究.硬X射线成像仪(HXI)是ASOS卫星的3大载荷之一,它通过对太阳活动发射的硬X射线进行傅里叶调制成像,实现高空间分辨率和高时间分辨率的太阳能谱成像观测.量能器单机是HXI的关键单机之一,其主要任务是精准测量通过每对光栅后太阳硬X射线的能量和通量.主要介绍了量能器单机的工作原理及其关键指标要求、标定设备及标定方案,最后给出了标定结果,从而验证了量能器单机方案设计的合理性.     

日冕物质抛射的观测性质

综述日冕物质抛射的观测和持性，简短的前言之后，给出ＣＭＥ的发现经过及统计特性，着重介绍ＣＭＥ与其他种类太阳活动的相关。然后介绍ＣＭＥ的一般特性，包括可能与ＣＭＥ相关的一些物理过程的观测特性。初步结论是：ＣＭＥ是一种演变中的磁结构现象。     

二维太阳光谱观测方法和技术

经典的太阳光谱观测是一维的，它有很大的局限性。从５０年代起，天文工作者采用多种方法开展二维太阳光谱观测，已经研制出一系列仪器，建立完整的资料归算程序，取得优良成果。在二维观测资料的基础上，用理论方法推出深度分布，可以得出三维的立体图像，这会成为太阳研究的主要方法之一。     

A substructure analysis of the A3558 cluster complex

The 'algorithm driven by the density estimate for the identification of clusters' ( DEDICA ) is applied to the A3558 cluster complex in order to find substructures. This complex, located at the centre of the Shapley Concentration supercluster, is a chain formed by the ACO clusters A3556, A3558 and A3562 and the two poor clusters SC 1327-312 and SC 1329-313. We find a large number of clumps, indicating that strong dynamical processes are active. In particular, it is necessary to use a fully three-dimensional sample (i.e. using the galaxy velocity as third coordinate) in order also to recover the clumps superimposed along the line of sight. Even though a large number of detected substructures was already found in a previous analysis, this method is more efficient and faster when compared with a wide battery of tests, and permits the direct estimate of the detection significance. Almost all subclusters previously detected by the wavelet analyses found in the literature are recognized by DEDICA . On the basis of the substructure analysis, we also briefly discuss the origin of the A3558 complex by comparing two hypotheses: (i) the structure is a cluster–cluster collision seen just after the first core–core encounter; or (ii) this complex is the result of a series of incoherent group–group and cluster–group mergings, focused in that region by the presence of the surrounding supercluster. We studied the fraction of blue galaxies in the detected substructures and found that the bluest groups reside between A3562 and A3558, i.e. in the expected position for the scenario of cluster–cluster collision.     

Stellar Abundance and Galactic Chemical Evolution through LAMOST Spectroscopic Survey

A project of a spectroscopic survey of Galactic structure and evolution with a Large sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) is presented. The spectroscopic survey consists of two observational modes for various targets in our Galaxy. One is a major survey of the Milky Way aimed at a systematic study of the stellar abundance and Galactic chemical evolution through low resolution (R=1000-2000) spectroscopy. Another is a follow-up observation with medium resolution (R = 10000) spectrographs aimed at detailed studies of the selected stars with different chemical composition, kinematics and dynamics.     

Galaxy activity in merging binary galaxy clusters

We present the results of a study of galaxy activity in two merging binary clusters (A168 and A1750) using the Sloan Digital Sky Survey (SDSS) data supplemented with the data in the literature. We have investigated the merger histories of A168 and A1750 by combining the results from a two-body dynamical model and X-ray data. In A168, two subclusters appear to have passed each other and to be coming together from the recent maximum separation. In A1750, two major subclusters appear to have started interaction and to be coming together for the first time. We find an enhanced concentration of the galaxies showing star formation (SF) or active galactic nuclei (AGN) activity in the region between two subclusters in A168, which were possibly triggered by the cluster merger. In A1750, we do not find any galaxies with SF/AGN activity in the region between two subclusters, indicating that two major subclusters are in the early stage of merging.     

Radio properties of the Shapley Concentration – IV.The A3528 cluster complex

We report and discuss the results of a 22-cm radio survey carried out with the Australia Telescope Compact Array (ATCA) covering the A3528 complex, a chain formed by the merging ACO clusters A3528–A3530–A3532 , located in the central region of the Shapley Concentration. Simultaneous 13-cm observations are also presented. Our final catalogue includes a total of 106 radio sources above the flux density limit of 0.8 mJy. By cross-correlation with optical and spectroscopic catalogues we found 32 optical counterparts, nine of them belonging to the A3528 complex.
We explored the effects of cluster mergers on the radio emission properties of radio galaxies by means of the radio luminosity function (RLF) and radio source counts. We found that the radio source counts are consistent with the background counts, as already found for the A3558 complex. The RLF for this complex is consistent, in both shape and normalization, with the general cluster luminosity function for early-type galaxies derived by Ledlow & Owen. This result is different from the one we obtained for the A3558 merging complex, the RLF of which is significantly lower than that derived by Ledlow & Owen.
We propose that the different stage of the merger is responsible for the different RLFs in the two cluster complexes in the core of the Shapley Concentration. The early stage of merger for the A3528 complex, proposed by many authors, may not yet have affected the radio properties of cluster galaxies, while in the more much advanced merger in the A3558 region we actually see the effects of this process on the radio emission.     

太阳磁场观测研究

简要回顾了近几年国际上太阳磁场研究的一些重要进展，包括耀斑与磁切和电流的关系，电流螺度和磁螺度，磁场拓扑性，三维磁场外推，色球磁场研究，日冕磁场研究，内网络磁元，磁流和振荡，极区磁场观测以及色球磁元观测等方面内容，同时也介绍了怀柔太阳观测站最近所取得的主要成果，自20世纪90年代以来，YOHKOH高分辨率的太阳X射线数据，SOHO的多波段大尺度观测，TRACE的高分辨太阳过渡区资料，为研究太阳磁场从内部到距离几十太阳半径处的大范围演化提供了依据，高效的空间资料结合长期的地面资料，将是正派推动太阳磁场研究的重要手段和必然趋势。     

A multicolor photometric study of the neglected eclipsing binary FT Ursae Majoris

The multicolor photometric observations of the neglected eclipsing binary FT Ursae Majoris (FT UMa) were obtained in 2010. The 2003 version of the Wilson-Devinney code was used to analyze the light curves in the B, V and R bands simultaneously. Based on the spectroscopic mass ratio q = 0.984 published by Pribulla et al., it is found that FT UMa is an evolved contact binary with a contact degree of 15.3%. The low amplitude of light variations, ～ 0.15 mag, arises mainly from a moderately low inclination angle...