An Analysis of Average Pulsar Profiles and A Study of the ρ-P relation of Pulsars     

Hua-Xiang Wang  Xin-Ji WuDepartment of Astronomy  Peking University  Beijing  Urumqi Astronomical Station  National Astronomical Observation  Urumqi CAS-PKU Joint Beijing Astrophysics Center  Beijing 《中国天文和天体物理学报》2003,3(5)

Using the method of Gaussian Fit Separation of Average Profile (GF-SAP), we re-examine the average profiles of nine pulsars at several frequencies, ranging from 408-1642 MHz. This method enables us to obtain the number of components for each pulsar, and the parameters for each component, the width, position and amplitude. The ρ-P relation for the inner cone and outer cone are studied separately, and the results are, respectively, ρ = p-0.51±0.05 and ρ= p-0.42±0.06 The results can be interpreted as a confirmation of the double-cone structure of pulsar emission beams. The altitudes of emission region, and the radius-to-frequency-map (RFM) are also examined; for the outer cone, we obtained γ(v) ∝v-0.19±0.09.  相似文献   

利用DiFX处理CVN天文观测数据进展     

江悟  沈志强  舒逢春  郭丽  闫振  陈中 《天文学进展》2014,(4)

相关处理机是VLBI观测数据处理的核心单元,相关处理机的输出结果可以直接作为天文成图、测地学以及航天器干涉测量等应用的输入。DiFX是运行在分布式计算、共享存储单元的集群环境下最成功的软件相关处理机之一。首先介绍上海天文台DiFX综合平台的现状;然后介绍利用DiFX相关处理机处理中国VLBI网(CVN)天文观测数据的进展:最后简短展望了DiFX平台为CVN及国际VLBI天文观测提供相关处理服务的前景。可为利用该平台的相关处理结果开展科学研究提供参考。  相似文献   

Relation of pulsars to the remnants of supernova bursts     

V. H. Malumyan  A. N. Harutyunyan 《Astrophysics》2006,49(1):88-95

Based on a large volume of statistical data it is shown that the spatial distributions of radio pulsars in the galaxy with characteristic ages T ≤ 10 ⁶ years and T > 10⁶ years differ significantly. The overwhelming majority of the pulsars with T ≤ 10 ⁶ years lie within a narrow band of width 400 pc around the galactic plane. A large portion of the pulsars with T > 10⁶ years is concentrated outside this zone. In the case of younger pulsars, a larger fraction of them lies within the confines of the above mentioned zone. It is also shown that pulsars with T ≤ 10 ⁶ years and the remnants of supernova explosions have essentially the same spatial distribution. These facts support the existence of a relationship between pulsars and supernova remnants, as well as the acquisition of high spatial velocities by pulsars during their birth. __________ Translated from Astrofizika, Vol. 49, No. 1, pp. 103–110 (February 2006).  相似文献   

脉冲星时间稳定度的估计方法     

仲崇霞  杨廷高 《时间频率学报》2004,27(1):48-53

对表征频率稳定度的σy(τ)和σz(τ)方法进行了分析比较。以PSRB1 855 0 9计时观测得到的脉冲星时为例 ,用两种方法估计了其频率稳定度。计算结果和分析表明σz(τ)方法更适合于估计脉冲星时间的频率稳定度  相似文献   

Measuring the proper motion of the pulsar Geminga using γ-ray data     

Cheng Ling-xiang  Sun Xue-jun  LI Ti-pei 《Chinese Astronomy and Astrophysics》1995,19(4):440-442

We have measured the right ascension of Geminga at different epochs by comparing the absolute phases between the different γ-ray observations. These values show that the right-ascension component of the proper motion of Geminga is 0.226±0.03 arcsec per year, which is consistent with that of G″, the most probable optical counterpart, thus independently confirming the correspondence between G″ and Geminga.  相似文献   

Pulsars in FIRST Observations     

Xiang－HuaLi  Jin－LinHan 《中国天文和天体物理学报》2002,2(2):146-150

1 INTRODUCTION Pulsars receive a large kick velocity during the period of birth, so they move away from theirbirth place, where the center of supernova remnant is believed to be. Measuring the propermotions of pulsars can derive an independent estimate of their ages, which has a number ofastrophysical uses, for example, in the studies of the evolution of neutron star magnetic fieldand of pulsar emission beam. There are three methods of measuring proper motion: (1) traditional optical metho…  相似文献   

Research on Ensemble Pulsar Time Based on Observed Data     

Ding Chen  Xing-zhi Zhu  Na Wang 《Chinese Astronomy and Astrophysics》2012

The applications of pulsar timing to several important aspects are introduced and a skeletal definition of the pulsar time scale is given. By taking advantage of the observational timing data of millisecond pulsars obtained at the Parkes Astronomical Observatory, Australia, the ensemble pulsar time based on 4 millisecond pulsars is built up, the comparison of its stability σz, with that of the atomic time is made, and finally a few of important factors which affect the ensemble pulsar time, as well as their influences on the pulsar timing accuracy and application are analyzed.  相似文献   

Variability of radiation from the Crab Nebula     

Yu. I. Neshpor  A. V. Zhovtan 《Bulletin of the Crimean Astrophysical Observatory》2009,105(1):115-118

We consider variations of the radiation from the Crab Nebula in two energy ranges: X-rays (2–10 keV) and very-high-energy (>1 TeV) gamma rays. We demonstrate the presence of sine-shaped quasi-periodic variations in the X-ray range, with the period P = 862 d. A positive correlation was detected between variations of X-rays and gamma rays (the HEGRA data) with time.  相似文献   

关于脉冲星脉冲到达时间转换方程   总被引：1，自引：0，他引：1  

杨廷高 《时间频率学报》2009,32(2):154-159

较详细地介绍了脉冲星脉冲到达时间（TOA）转换方程,讨论了脉冲星TOA转换方程在航天器导航算法中的具体应用问题。同时,对导航用的脉冲星脉冲TOA转换方程与地面射电计时观测用的脉冲星脉冲TOA转换方程进行了比较研究。  相似文献   

射电脉冲星的逆康普顿散射（ICS）模型和偏振观测     

乔国俊  徐仁新 《紫金山天文台台刊》1999,18(3):285-292

近来我们在射电脉冲星的逆康普顿散射模型,致密星物理以及一些相关问题上做了下列几项工作：１） 对脉冲星物理中的一系列基本理论进行了较深入的研究,包括对裸奇异星比中子星更可能是射电脉冲星之起源的观点的论证。２） 进一步发展了射电脉冲星的逆康普顿散射（ＩＣＳ） 模型并完成了一系列相关工作。３） 进行了脉冲星的偏振分析和有关观测工作,并用其结果对银河系磁场和旋臂结构进行了分析。４） 研究了黑洞脉冲星双星系统的一些特性,为黑洞的搜寻工作作了初步准备。  相似文献