A new method to analyse pulsar nulling phenomenon  

作　　者：YANG AiYuan HAN JinLin WANG Na 

机构地区：[1]Xinjiang Astronomical Observatory,Chinese Academy of Sciences [2]The University of Chinese Academy of Sciences [3]National Astronomical Observatories,Chinese Academy of Sciences

出　　处：《Science China(Physics,Mechanics & Astronomy)》2014年第8期1600-1606,共7页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by China Ministry of Science and Technology(Grant No.2013CB837900);the National Natural Science Foundationof China(Grant Nos.10833003,11003023,11273029 and 11261140641)

摘　　要：Pulsar hulling is a phenomenon of sudden cessation of pulse emission for a number of periods. The nulling fraction was often used to characterize the phenomenon. We propose a new method to analyse pulsar hulling phenomenon, by involving two key parameters, the nulling degree, X, which is defined as the angle in a rectangular coordinates for the numbers of nulling periods and bursting periods, and the nulling scale, N, which is defined as the effective length of the consecutive nulling periods and bursting periods. The nulling degree X can be calculated by tanX = Nnulling/Nbursting and the mean is related to the nulling fraction, while the nulling scale, N, is also a newly defined fundamental parameter which indicates how often the nulling occurs. We determined the distributions ofx and N for 10 pulsars by using the data in literature. We found that the nulling degree X indicates the relative length of nulling to that of bursting, and the nulling scale N is found to be related to the derivative of rotation frequency and hence the loss rate of rotational energy of pulsars. Their deviations reflect the randomness of the nulling process.Pulsar nulling is a phenomenon of sudden cessation of pulse emission for a number of periods.The nulling fraction was often used to characterize the phenomenon.We propose a new method to analyse pulsar nulling phenomenon,by involving two key parameters,the nulling degree,χ,which is defined as the angle in a rectangular coordinates for the numbers of nulling periods and bursting periods,and the nulling scale,N,which is defined as the effective length of the consecutive nulling periods and bursting periods.The nulling degreeχcan be calculated by tanχ=Nnulling/Nburstingand the mean is related to the nulling fraction,while the nulling scale,N,is also a newly defined fundamental parameter which indicates how often the nulling occurs.We determined the distributions ofχand N for 10 pulsars by using the data in literature.We found that the nulling degreeχindicates the relative length of nulling to that of bursting,and the nulling scale N is found to be related to the derivative of rotation frequency and hence the loss rate of rotational energy of pulsars.Their deviations reflect the randomness of the nulling process.

关 键 词：PULSARS radio sources radiation mechanisms 

分 类 号：P145.6[天文地球—天体物理]