射电脉冲星的相干辐射机制

With the framework of the pulsar cap model for the pulsar, three possible coherent emission mechanisms for radio pulsars are briefly discussed. These are coherent curvature emission, relativistic plasma emission, and linear acceleration emission, respectively.     

射电脉冲星观测资料及其启示

在本文中先简要介绍了８０年代以来射电脉冲星方面的观测进展，然后详细介绍了射电脉冲星的第一手观测资料，包括空间分布，传播特性，时间特性，脉冲轮廓与偏振以及频谱特性等，并详细综述观测资料对我们提供的信息及给我们的启示，为理论模型的建立和检验提供了基础。     

候选射电脉冲星的预测

对已知脉冲星大样本的统计和分析表明,绝大多数脉冲星的线偏振大于１０％,谱指数低于－１,比较了脉冲星和射电类星体及致密陡谱源的频谱和偏振特性的差别,以高线偏振,高谐系数,高银纬及在低频下较低流量等作为射电脉冲星候选的判据,从新近释放的ＶＬＡ巡天和ＷＳＲＴ巡天结果中挑选出一个较粗的候选脉冲星样本。进一步考虑近期在部分天区中已作过高灵敏度的脉冲星巡天,所有落入这些天区内的候选源也都从本样本中排出,以候     

脉冲星的射电发射

脉冲星的射电辐射与其他天体物理辐射源有很大的不同，因为它们有着极高的亮温度和高度的线或圆偏振。极高的亮温度意味着起作用的发射机制一定是相干的。至今尚无对这种辐射普遍接受的模型。本文讨论了关于脉冲星的射电辐射产生和传播研究中的新进展。     

射电脉冲星搜寻工作的进展

评述了射电脉冲星搜寻及观测研究的巨大贡献和重要意义，分析了影响脉冲星搜寻工作的几个关键因素（如灵敏度，色散，观测频率及设备等），着重介绍和分析了自发现脉冲星（特别是发现第一颗秒脉冲星）以来所进行的卓有成效的脉冲星搜寻工作（包括脉冲星的早期寻，毫秒脉冲星的初期搜寻，高银续脉冲星搜寻，定向搜寻以及进一步的广域深空搜寻等）的情况，结果，意义和进展。     

射电脉冲星锥成分的谱行为

选取２３颗双峰轮廓脉冲星,考察脉冲星射电辐射锥成分的谱行为．通过对前导和后随成分峰值强度比与频率的关系进行幂律谱拟合,给出了前后两部分的相对谱指数．结果显示,大多数脉冲星的相对谱指数集中分布在零附近,这表明,前导和后随成分的辐射本质上没有差别;相对谱指数的近似高斯分布显示出,其辐射部位高辐射束中心距离之差具有一定的随机性．     

类Crab脉冲星的三维磁层外隙模型

利用三维脉冲星磁层模型研究了磁层外隙的几何结构,首先用自治模型确定“外隙”的垂直尺度,在该模型中外隙尺度受回流的外隙流（带有隙加速的带电粒子发射的曲率光子）加热极帽而产生的热光子的碰撞而成对生成所限,外隙的横向尺度也受本地对生成所限,在脉冲星的磁层中,原则上有两个拓扑分离的外隙,允许同时进入和流出粒子,不过,流入粒子流产生的辐射形态受隙了本地对生成和恒星附近的磁对生成的严格制约,根据外隙及其本地结构的三维模型计算了类Crab脉冲星的辐射和相位分解谱。     

射电脉冲星1822—09微脉冲的性质

The relation between intensity and duration time of micropulses for PSR 1822-09 is studied for comparison with the nonlinear temporal model. The product of intensity and duration lime of micropulses is roughly constant (SpT= 1035 0.2 ). Such relation is consistent with theoretical predictions of the nonlinear temporal model proposed by Chian and Kennel (1983).     

射电脉冲星锥成分的谱行为

选取２３颗双峰轮廓脉冲星,考察脉冲星射电辐射锥成分的谱行为,通过对前导和后随成分峰值强度比与频率的关系进行幂律谱拟合,给出了前后两部分的相对谱指数,结果显示,大多数脉冲星的相对谱指数集中分布在零附近,这表明,前导和后随成分的辐射本质上滑有差别;相对谱指数的近似高斯分布显示出,其辐射部位离辐射束中心距离之差具有一定的随机性。     

Magnetorotational and Tayler Instabilities in the Pulsar Magnetosphere

The magnetospheres around neutron stars should be very particular because of their strong magnetic field and rapid rotation. A study of the pulsar magnetospheres is of crucial importance since it is the key issue to understand how energy outflow to the exterior is produced. In this paper, we discuss magnetohydrodynamic processes in the pulsar magnetosphere. We consider in detail the properties of magnetohydrodynamic waves that can exist in the magnetosphere and their instabilities. These instabilities lead to formation of magnetic structures and can be responsible for short-term variability of the pulsar emission.     

Pulsar Radio and Gamma-Ray Emission

A total of eight gamma-ray sources are identified with pulsars and these include some of the strongest gamma-ray sources in the sky. About 20 of the unidentified gamma-ray sources are very likely to be associated with currently known pulsars and there is little doubt that many of the others, at least those at low Galactic latitudes, will ultimately be identified with pulsars. How many of these and future gamma-ray detections will be detectable at radio wavelengths depends on the details of the radio and gamma-ray beaming. There is good evidence that the radio beams in young and millisecond pulsars are very wide, implying that most gamma-ray pulsars will be detectable in the radio band.     

Toroidal Magnetic Field Generation in the Magnetosphere of Crab Pulsar

Plasma mechanism for the generation of toroidal magnetic field in the magnetosphere of Crab pulsar is presented. The mechanism is based on the development of parametric type instability in the relativistic electron-positron plasma of the pulsar magnetosphere. As a result of plasma corotation with pulsar and its magnetic field, the effect of plasma radial braking takes place and the time dependence of plasma particle radial velocity is harmonic. This triggers the development of parametric type instability in the relativistic plasma of the pulsar magnetosphere. The energy for this process is drawn from the slowing down of pulsar rotation.     

12种射电爆发及其辐射机制

系统地研究了太阳活动区上空闭合磁场域和开放磁场域俘获的高能电子的运动特性,所产生的自然波属性及观测特性。探讨了１２种射电爆发的辐射机制。     

The Radial Structure of Pulsar Radio Emission Regions

An important paramter in the study of the radial structure of the pulsar radio emission region is the altitude of the emission,but this cannot be derived directly from the observations.The altitude can be expressed as a function of frequency,rν∝ν^-ξ,and the method of K analysis can be used to calculate the power law index ξfrom observations at different frequencies,We have calculated the value of ξ for 18 pulsars observed at two frequencies,610MHz and 1408MHz and for three pulsars observed at three or more frequencies,The average value of ξis 0.27,which indicates that the emission altitude increases with decreasing frequency and that the radial structure is compact.     

A Solar Stationary Type IV Radio Burst and Its Radiation Mechanism

A stationary Type IV (IVs) radio burst was observed on September 24, 2011. Observations from the Nançay RadioHeliograph (NRH) show that the brightness temperature (\(T_{\mathrm{B}}\)) of this burst is extremely high, over \(10^{11}\) K at 150 MHz and over \(10^{8}\) K in general. The degree of circular polarization (\(q\)) is between \(-60\% \sim -100\%\), which means that it is highly left-handed circularly polarized. The flux–frequency spectrum follows a power-law distribution, and the spectral index is considered to be roughly \(-3 \sim -4\) throughout the IVs. Radio sources of this event are located in the wake of the coronal mass ejection and are spatially dispersed. They line up to present a formation in which lower-frequency sources are higher. Based on these observations, it is suggested that the IVs was generated through electron cyclotron maser emission.     

用50m射电望远镜作脉冲星观测与研究

国家天文台正在研制的50m射电望远镜将投入脉冲星观测与研究，推动我国的脉冲星工作。本文回顾了自第1颗脉冲星发现后35年来脉冲星观测取得的成果，和理论研究获得的重大进展，并讨论我国脉冲星工作可能开展的观测与研究。当今世界脉冲星观测与研究虽然还有许多遗留问题，但是作为中子星基本观测事实已被确认。脉冲星的应用也已经走上了历史舞台。如果利用50m射电望远镜对脉冲星的特殊活动现象进行观测与研究，可能获得突破性的进展。     

Influence of Neutron Star Parameters on Evolutions of Different Types of Pulsar

Influences of the mass, moment of inertia, rotation, absence of stability in the atmosphere and some other parameters of neutron stars on the evolution of pulsars are examined. It is shown that the locations and evolutions of soft gamma repeaters, anomalous X-ray pulsars and other types of pulsar on the period versus period derivative diagram can be explained adopting values of B < 10¹⁴ G for these objects if they have smaller mass (e.g. about 0.5 Solar mass) compared to the conventionally adopted values of mass. This approach gives the possibility to explain many properties of different types of pulsar.