posted on 2024-08-06, 12:04authored byA. Parthasarathy, Ryan ShannonRyan Shannon, S. Johnston, L. Lentati, Matthew BailesMatthew Bailes, S. Dai, M. Kerr, R. N. Manchester, Stefan Oslowski, C. Sobey, Willem van Straten, P. Weltevrede
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-(E) over dot radio pulsars observed for similar to 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 (beta). We measure the median Ared to be -10.4(-1.7)(+1.8) yr(3/2) and ss to be -5.2(-3.8)(+3.0) and show that the strength of timing noise scales proportionally to nu(1)vertical bar(nu) over dot vertical bar(-0.6 +/- 0.1), where. is the spin frequency of the pulsar and.. 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.
Funding
ARC Centre of Excellence for Gravitational Wave Discovery