Particle Outflow and Pulsar Timing Noise
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Transcript of Particle Outflow and Pulsar Timing Noise
Particle Outflow and Pulsar Timing Noise
Xiong Wei Liu
2011-05-09
Based on: Chin. Phys. Lett. Vol. 28, No. 1 (2011) 019701
Department of Astronomy, Peking University
Outline
•Background;
•Our Model;
•Observational Checking;
•Discussion.
Background
Theoretically, pulsars spin stably
Standard Clock
GW detection
Observationally, timing niose exist everywhere
Explainations for timing noise:
a. unmodelled companions;
b. gravitational waves;
c. free-precession of neutron star.
...
But, timing noise still can’t be eliminated completely, especially the noise in long timescale of years.
Background
Our Model
Main Idea: A new kind of intrinsic Timing Noise of pulsar
Theoretical Basis: The Partical outflow from a pulsar should be unstable , so is the spin of the pulsar
(Xu & Qiao 2001 ApJL. 561 L85)
dE
uE is the power carried away by relativistic particles which rise from unipolar induction, and is the power of magnetic dipole radiation. is the variation.
Observational Clue: Variations of flux density may indicate
the variations of particle outflow
Our Model
Theoretical Result: The relationship between variations of particle outflow and Timing Noise
The longer, the stronger the noise!
Our Model
Variations of particle outflow Timing noise
140 0 0(1 ) 0.1 , 1 10Take n P s P
Simulation:
Our Model
Resemble with observations: Profile feature, range feature and time dependence
Our Model
Estimate from
Observational Checking
Checking 1: Relationship between Timing Noises and distribution of pulsars
Ryan M. et al. (arXiv:1010.4794v1)Statistics from approximately 450 distinct pulsars
Checking 2: Relationship between spin frequency, frequency derivative and Timing Noise
Observational Checking
Cordes & Downs (1985) and D’Alessandro et al.(1995)
Ryan M. et al. (arXiv:1010.4794v1)
Checking 3: Random walks in frequency and frequency derivative–Phenomenon and the essence
Observational Checking
Discussion
New mechanism of TN: The fluctuation of particle outflow can lead to significant timing noise in long time span of years.
New Challenges: Intrinsic Timing Noise, unavoidable!
The millisecond pulsars chose to detecting GW or act as Standard Clock, which haven’t found signigicant long time span TNs, will effect by their intrinsic TNs in longer time
New Question: How to avert the bad effect of this kind of TNs?