1. Speaker：Yi Xie 2014-04-30 Lunch Talk
Pulsar timing noises as evidence of Hall drift and Hall Weves in crusts of isolated neutron stars
Speaker：Yi Xie
Lunch Talk

2. Pulsars: The Most Stable Rotators

3. Observed pulse series

5. Irregular Period Changes
Two Main Types of Irregularity：
Timing noise : low-frequency structures
Glitches:
classical glitches and slow glitches
Hobbs et al. 2010

6. Secular Period Changes

7. Zhang & Xie a

8. Zhang & Xie. 2013

9. Xie & Zhang submitted

12. Motivation: two issues in controversial
1. The long-term evolution of magnetic fields for individual pulsars?
Our model suggests that the evidence may probably be shown in pulsars with
2. The physical origin of pulsar timing noise?
The evidence for effective magnetic field evolution

13. Lyne et al. 2010

14. Lyne et al. 2010
VS ?

15. Sample selection

16. B :
rule out！
Theory :
reported:
Slope for
error:

18. The allowed area in the Theta-Beta Plane
Reported:
P. A. gives:

20. Xie & Zhang 2013 submitted.

21. Physical Implications

22. Hall Drift
Reported:
The majority of dipolar magnetic field lines are restricted to their outer crusts!

23. Magnetic field configuration

24. Hall Waves

25. Model: Hall wave induce changes of the areas of polar regions, producing pulse shape changes:
Assume:

26. Observed and derived parameters for the pulsars:
Xie & Zhang 2013 submitted.

30. Summary and discussion
This is the first time that the Hall drift and Hall waves are observationally identified in individual pulsars, which are responsible for the observed long-term evolution of the spin-down rates and their quasi-periodic modulations, respectively.
The majority of dipolar magnetic field lines are restricted to their outer crusts.
Millisecond pulsars have much weaker dipole magnetic fields, implying much smaller and , which is actually the basis for using them to detect gravitational waves.

32. Periodicity in Timing Noise
Hobbs et al. 2010
：period 4.38 yr

33. 南山 25米
脉冲到达时间：实测与模型之间的差值叫残差。
残差不是白噪声：模型没有考虑到：自行、进动、伴 星、自转不稳定性（跃变和到达时间噪声）。

34. Mean Pulse Profiles 脉冲星的平均轮廓 PSR B0329+54 P=0.7145 s PSR B0531+21
P=33 ms（蟹状星云脉冲星）
PSR
P=5.75ms
PSR B
P=1.557ms
每秒642转！