Assessing the effects of timing irregularities on radio pulsars anomalous braking indices

A study of 366 radio pulsars at Jodrell Bank Observatory reveals that anomalous braking indices—deviations from expected spin-down behavior—are largely artifacts caused by timing irregularities, either intrinsic or extrinsic to the pulsar system. For a subsample of 223 pulsars exhibiting consistent timing noise over decades, strong correlations (|r| ∼ 0.80–0.90) were found between the second derivative of observed frequency and timing activity parameters, suggesting these irregularities originate from intrinsic neutron star processes. Conversely, no significant correlations (r < 0.3) were detected in the remaining 143 pulsars, where white noise fluctuations dominate, implying external sources. This distinction supports the hypothesis that timing noise in isolated pulsars stems from internal spin-down mechanisms, while white noise arises externally.

Chukwude, A. E., & Odo, F. C. (2016). Assessing the effects of timing irregularities on radio pulsars anomalous braking indices. Research in Astronomy and Astrophysics, 16(10), 150. https://doi.org/10.1088/1674-4527/16/10/150