Study Of The Pulsar Timing Noise Results From The Fall-back Disk Instability

The period of pulsars is very stable.But there is an irregular deviation about time of arrival(TOA)between the measurement and the prediction,and it is called timing noise.It reflects the influence of unknown factors on TOA.In this paper,we researched that timing noise may be caused by the micro-disturbance of the moment.When the pulsar braked by a fall-back disk,the instability of the fall-back disk will cause timing noise of the pulsar.In this paper,we reviewed the history of pulsar research and its observational characteristics firstly,and then introduced the data processing of pulsar timing noise and the research about fall-back disk braking pulsar.In the fourth section of the paper,we studied that timing noise influenced by three factors respectively which are from the random fluctuation of fall-back disk accretion rate,and the three factors are fluctuation's intensity,time scale of variation and time correlation.We know that,(i)The timing noise is relatively larger by the larger fluctuation intensity of accretion rate.When the fluctuation of random sequence is reduced to a certain level,timing noise becomes to the obviously wave form of single peak.(ii)The shorter the time scale of variation,the smaller the timing noise is.(iii)In the short term,the bigger the accretion rate's Hurst parameter,the bigger the timing noise is.With the increase of observation time,the amplitude variation of timing noise is significant by time-nonindependent random sequence,and not significant by time-dependent random sequence.(iv)The timing noise's increment of standard deviation calculated by this model is the same as other works.