pulsar timing noises as evidence of hall drift and hall weves in crusts of isolated neutron stars
DESCRIPTION
Pulsar timing noises as evidence of Hall drift and Hall Weves in crusts of isolated neutron stars. Speaker ： Yi Xie 2014-04-30 Lunch Talk. Pulsars: The Most Stable Rotators. Observed pulse series. Irregular Period Changes. Two Main Types of Irregularity ： - PowerPoint PPT PresentationTRANSCRIPT
Pulsar timing noises as evidence of Hall drift and Hall Weves in cru
sts ofisolated neutron stars
Speaker ： Yi Xie
2014-04-30 Lunch Talk
Pulsars: The Most Stable Rotators
Observed pulse series
Irregular Period ChangesTwo Main Types of Irregularity ： Timing noise : low-frequency structures
Glitches:
classical glitches and slow glitches
Hobbs et al. 2010
Secular Period Changes
Zhang & Xie. 2012 a
Zhang & Xie. 2013
Xie & Zhang. 2013 submitted
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
Lyne et al. 2010
Lyne et al. 2010
VS ?
Sample selection
error:
rule out ！
reported:
B1828-11:
Theory :
Slope for
P. A. gives: Reported:
The allowed area in the Theta-Beta Plane
Xie & Zhang 2013 submitted.
Physical Implications
Reported:
The majority of dipolar magnetic field lines are restricted to their outer crusts!
Hall Drift
Magnetic field configuration
Hall Waves
Model: Hall wave induce changes of the areas of polar regions, producing pulse shape changes:
Assume:
Xie & Zhang 2013 submitted.
Observed and derived parameters for the pulsars:
2009-2-06
• 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.
Summary and discussion
2009-2-06
2009-2-06
Periodicity in Timing NoisePeriodicity in Timing Noise
• 1540-06 ： period 4.38 yr
Hobbs et al. 2010
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）。
南山 25米
Mean Pulse Profiles Mean Pulse Profiles 脉冲星的平均轮廓脉冲星的平均轮廓
PSR B0329+54
P=0.7145 s
PSR B1937+21
P=1.557ms
每秒 642 转！
PSR 0437+4715
P=5.75ms
PSR B0531+21
P=33 ms （蟹状星云脉冲星）
