Optical flares from the faint mid‐dM star 2MASS J00453912+4140395

We present B and V light curves of a large stellar flare obtained with the Wide Field Camera at the Isaac Newton 2.5‐m telescope (La Palma). The source object is a faint (m_V = 21.38) foreground star in the field of the Andromeda galaxy, with its most probable spectral type being dM4. We provide an estimate of the total flare energy in the optical range and find it to be of the order of 1035 erg. The cooling phase of the large flare shows three additional weak flare‐like events, which we interpret as results of a triggering mechanism also observed on the Sun during large coronal mass ejections. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Variable and broad iron lines around black holes

“Variable and Broad Iron Lines around Black Holes” was the topic of the first scientific workshop organized by the XMMNewton Science Operations Centre. This foreword gives a brief introduction to the history of black hole research, which motivated the workshop's scientific topic. The organizing committees are listed and the meeting is shortly outlined. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

中低温热储及其井中热场

中低温地下热水有着广阔的开发利用前景,其成因及赋存规律的研究,是合理勘探、开发的基础。本文从地层、构造及水文地质条件入手,根据地热传导原理,研究了传导型热储的发育条件,划分了主要热储类型。在此基础上,对井(孔)中热场及井液温度变化规律进行了分析,给出了井液温度分布曲线及井液温度变化与地层的对应关系。该成果对勘探开发地下热水有指导意义。      

Microwave enhancement in coronal holes: Statistical properties

We report on the statistical properties of the microwave enhancement (brightness temperature, area, fine structure, life time and magnetic field strength) in coronal holes observed over a period of several solar rotations.     

232 MHz太阳爆发与日冕物质抛射

利用综合孔径射电望远镜在 ２３２ ＭＨｚ观测太阳,具有 ３·８’的空间分辨率、 ２０ ｍｓ 的时间分辨率和高灵敏度及很好的抗干扰能力．１９９９年共观测到１２次大爆发,其中８次与日冕物质抛射相关．可以利用米波射电爆发预报ＣＭＥ事件．     

射电类星体B3 1637+436A双峰轮廓宽发射线的光变研究

通过对比间隔17yr (静止系12.5yr)的Sloan Digital Sky Survey (SDSS)、Keck LRIS (Low-Resolution Imaging Spectrograph)和Baryon Oscillation Spectroscopic Survey (BOSS)的光学光谱, 对宽线双峰射电类星体B3 1637+436A的吸积盘性质做了初步研究.该类星体的SDSS (2001年5月21日)和Keck LRIS (2003年6月28\lk 日)的连续谱没有明显差异, 而BOSS (2018月6月17日)连续谱在V波段比SDSS暗了约1.2星等.这3条光谱的Hα宽发射线均表现出明显的双峰轮廓. 和连续谱一样, 宽线双峰的发射线轮廓也被认为是来自于吸积盘.通过上述3条光谱的Hα宽线双峰的盘模型拟合发现: BOSS光谱的Hα宽线双峰可以用单个盘模型很好地拟合,谱线发射区距离中心黑洞约900--3000引力半径. 而SDSS和Keck LRIS的Hα双峰轮廓需要用两个盘模型拟合, 对应的吸积盘发射区有两个区域,其中一个发射区(``外盘'')与BOSS类似, 另一个发射区(``内盘'')位于约400--900引力半径范围内, 到中心黑洞的距离显著小于外盘. 结合连续谱的光变特征,推测内盘消失是造成SDSS/Keck LRIS光谱和BOSS光谱在连续谱和发射线轮廓上同时发生光变的主要原因.     

Formation of Transient Coronal Holes during the Eruption of a Quiescent Filament and its Overlying Sigmoid

By using Hα, He I 10830, EUV and soft X-ray (SXR) data, we examined a filament eruption that occurred on a quiet-sun region near the center of the solar disk on 2006 January 12, which disturbed a sigmoid overlying the filament channel observed by the GOES-12 SXR Imager (SXI), and led to the eruption of the sigmoid. The event was associated with a partial halo coronal mass ejection (CME) observed by the Large Angle and Spectrometric Coronagraphs (LASCO) on board the Solar and Heliospheric Observatory (SOHO), and resulted in the formation of two flare-like ribbons, post-eruption coronal loops, and two transient coronal holes (TCHs), but there were no significantly recorded GOES or Hα flares corresponding to the eruption. The two TCHs were dominated by opposite magnetic polarities and were located on the two ends of the eruptive sigmoid. They showed similar locations and shapes in He Ⅰ 10830, EUV and SXR observations. During the early eruption phase, brightenings first appeared on the locations of the two subsequent TCHs, which could be clearly identified on He Ⅰ 10830, EUV and SXR images. This eruption could be explained by the magnetic flux rope model, and the two TCHs were likely to be the feet of the flux rope.     

Analysis of the spectrum of the coronal condensation of the total eclipse of 1983 June 11

We analyzed the spectrum of a coronal condensation observed during the total eclipse of 1983 June 11. Under the assumption of rotational symmetry we found the distributions of the electron density and the temperature. The electron density was higher in the centre of the condensation than on the edge. From different line pairs the maximum electron density was found to be between 1.7 3.5×10⁹cm⁻³ while the temperature was found to be basically uniform at 1.7 2.7×10⁶K. The turbulence velocity was 15 35km/s. The systematic flow of the condensation region with respect to the quiet corona was not more than 15km/s. Discussion of the instrumental profile showed that its effect was small on lines that were much wider than the profile.     

Dynamical properties of a centrifugally driven outflow from a disc near a black hole

The inclination of the field lines at the surface of the disc plays a crucial role on the nature of the magnetically driven flows. For the non-relativistic case, a centrifugally driven outflow of matter from the disc is possible, if the poloidal component of the magnetic field makes an angle of less than a critical 60° with the disc surface (Blandford and Payne 1982). We investigate the dynamical properties of the magnetically driven flows from the disc near a non-rotating black hole and find that the critical angle becomes larger than 60° when the flows start from the region near the black hole.     

磁能和磁复杂性向日冕的传输

本文讨论了从太阳光球向日冕传输磁能和磁复杂性的过程。活动日冕，作为由电磁场和粒子组成的系统，其唯一的开场表面是太阳光球。光球层等离子体的运动和磁场的相互作用，是造成磁能和磁复杂性向日冕传播的主要根源；同时，光球上的耗散过程也对日冕磁能和磁复杂性的积累有不可忽视的贡献。