A Statistical Analysis of Radio Pulsar Timing Noise

2007 ◽  
Vol 7 (4) ◽  
pp. 521-530 ◽  
Author(s):  
A. E Chukwude
2000 ◽  
Vol 177 ◽  
pp. 63-64
Author(s):  
W. Lewandowski ◽  
M. Konacki ◽  
M. Redmerska ◽  
G. Feiler ◽  
A. Wolszczan

Accurate, long-term timing measurements of pulsars provide a powerful method to study a variety of astrophysical phenomena. For “normal”, slow pulsars, the dominant factors that limit the timing precision are the intrinsic timing noise and single pulse “jitter” (e.g. Cordes 1993). In fact, because the pulse jitter surpasses radiometer noise for sufficiently strong pulsars and no further improvement of the timing precision can be achieved by increasing the antenna gain, the timing of such sources can be very efficiently conducted with suitably equipped medium-size radiotelescopes.We have been timing slow pulsars with the 32-m TCfA radiotelescope in Toruń, Poland, since July 1996, using a dual-channel, circular polarization L-band receiving system at frequencies around 1.7 GHz, and a 2 × 64 × 3 MHz channel pulsar backend, the Penn State Pulsar Machine - 2 (PSPM-2; for more details, see Konacki et al. 1999). Our gradually expanding source list currently includes 88 pulsars timed once a week with a millisecond precision using the observatory’s UTC-calibrated H-maser clock. Data analysis is routinely performed with the TEMPO software package. With a particularly dense, weekly sampling and a ≤1 ms timing precision, the TCfA program has a sensitivity to detect previously overlooked short period, low orbital inclination binaries, as well as very low-mass, planetary companions. In addition, it will be very useful in identifying and monitoring pulsar timing glitches and other forms of the timing noise.


1981 ◽  
Vol 245 ◽  
pp. 1060 ◽  
Author(s):  
J. M. Cordes ◽  
G. Greenstein

2011 ◽  
Vol 412 (4) ◽  
pp. 2678-2684 ◽  
Author(s):  
X. S. Na ◽  
N. Wang ◽  
J. P. Yuan ◽  
Z. Y. Liu ◽  
A. Esamdin ◽  
...  

1992 ◽  
Vol 128 ◽  
pp. 143-146
Author(s):  
S. E. Thorsett

AbstractA general feature of many models of the pulsar emission mechanism is that radiation of different frequencies is produced at different altitudes above the polar cap. The broadening of pulse components and increasing separation between components at low frequency is in general agreement with these theories. We review the available average profile and pulsar timing observations and discuss the implications for theories of radius-to-frequency mapping.


2019 ◽  
Vol 488 (2) ◽  
pp. 2190-2201 ◽  
Author(s):  
X J Liu ◽  
M J Keith ◽  
C G Bassa ◽  
B W Stappers

Abstract We investigate the impact of noise processes on high-precision pulsar timing. Our analysis focuses on the measurability of the second spin frequency derivative $\ddot{\nu }$. This $\ddot{\nu }$ can be induced by several factors including the radial velocity of a pulsar. We use Bayesian methods to model the pulsar times-of-arrival in the presence of red timing noise and dispersion measure variations, modelling the noise processes as power laws. Using simulated times-of-arrival that both include red noise, dispersion measure variations, and non-zero $\ddot{\nu }$ values, we find that we are able to recover the injected $\ddot{\nu }$, even when the noise model used to inject and recover the input parameters are different. Using simulations, we show that the measurement uncertainty on $\ddot{\nu }$ decreases with the timing baseline T as Tγ, where γ = −7/2 + α/2 for power-law noise models with shallow power-law indices α (0 < α < 4). For steep power-law indices (α > 8), the measurement uncertainty reduces with T−1/2. We applied this method to times-of-arrival from the European Pulsar Timing Array and the Parkes Pulsar Timing Array and determined $\ddot{\nu }$ probability density functions for 49  millisecond pulsars. We find a statistically significant $\ddot{\nu }$ value for PSR B1937+21 and consider possible options for its origin. Significant (95 per cent C.L.) values for $\ddot{\nu }$ are also measured for PSRs J0621+1002 and J1022+1001, thus future studies should consider including it in their ephemerides. For binary pulsars with small orbital eccentricities, such as PSR J1909−3744, extended ELL1 models should be used to overcome computational issues. The impacts of our results on the detection of gravitational waves are also discussed.


2019 ◽  
Vol 489 (3) ◽  
pp. 3810-3826 ◽  
Author(s):  
A Parthasarathy ◽  
R M Shannon ◽  
S Johnston ◽  
L Lentati ◽  
M Bailes ◽  
...  

ABSTRACT The smooth spin-down of young pulsars is perturbed by two non-deterministic phenomenon, glitches, and timing noise. Although the timing noise provides insights into nuclear and plasma physics at extreme densities, it acts as a barrier to high-precision pulsar timing experiments. An improved methodology based on the Bayesian inference is developed to simultaneously model the stochastic and deterministic parameters for a sample of 85 high-$\dot{E}$ radio pulsars observed for ∼10 yr with the 64-m Parkes radio telescope. Timing noise is known to be a red process and we develop a parametrization based on the red-noise amplitude (Ared) and spectral index (β). We measure the median Ared to be $-10.4^{+1.8}_{-1.7}$ yr3/2 and β to be $-5.2^{+3.0}_{-3.8}$ and show that the strength of timing noise scales proportionally to $\nu ^{1}|\dot{\nu }|^{-0.6\pm 0.1}$, where ν is the spin frequency of the pulsar and $\dot{\nu }$ is its spin-down rate. Finally, we measure significant braking indices for 19 pulsars and proper motions for 2 pulsars, and discuss the presence of periodic modulation in the arrival times of 5 pulsars.


1980 ◽  
Vol 239 ◽  
pp. 640 ◽  
Author(s):  
J. M. Cordes ◽  
D. J. Helfand
Keyword(s):  

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