# The ubiquity of variable radio emission and spin-down rates in pulsars

**Authors:** M. E. Lower, A. Karastergiou, S. Johnston, P. R. Brook, S. Dai, M. Kerr, R. N. Manchester, L. S. Oswald, R. M. Shannon, C. Sobey, P. Weltevrede  
**arXiv:** [2501.03500](https://arxiv.org/abs/2501.03500)  
**Date:** 2025-01-07  
**Summary page:** https://www.summarizepaper.com/en/paper/2501.03500v3/

## Key points

- Study title: "The ubiquity of variable radio emission and spin-down rates in pulsars"
- Researchers involved: M. E. Lower, A. Karastergiou, S. Johnston, P. R. Brook, S. Dai, M. Kerr, R. N. Manchester, L. S. Oswald, R. M. Shannon, C. Sobey and P.Weltevrede
- Investigation of 259 isolated radio pulsars over three decades at Parkes 64 m radio telescope
- Use of Gaussian process regression and Bayesian inference techniques
- 238 pulsars displayed variability in spin-down rates
- 52 pulsars showed changes in profile shape
- Identification of 23 known state-switching pulsars within the group
- Positive correlation between spin-down fluctuations and increasing spin-down rates
- Challenges traditional understanding of pulsar stability
- Highlights a previously unrecognized trend among pulsars
- Significant implications for gravitational wave searches through ensemble timing of millisecond pulsars
- Need for further research to fully understand these astronomical phenomena

## Summary

A recent study titled "The ubiquity of variable radio emission and spin-down rates in pulsars" by researchers M. E. Lower, A. Karastergiou, S. Johnston, P. R. Brook, S. Dai, M. Kerr, R. N. Manchester, L. S. Oswald, R. M. Shannon, C. Sobey and P.Weltevrede has investigated the behavior of 259 isolated radio pulsars over the past three decades at the Parkes 64 m radio telescope known as Murriyang using Gaussian process regression and Bayesian inference techniques. The results of the study revealed that a significant number (238) of these pulsars displayed variability in their spin-down rates and 52 also showed changes in profile shape.This discovery challenges the traditional understanding of pulsar stability and highlights a previously unrecognized trend among these celestial objects. Additionally,the researchers identified 23 known state-switching pulsars within this group,making it the largest catalogue of variable pulsars to date.This finding suggests that variability in spin-down rates and profile shapes is common across a broader population of pulsars than previously thought. Interestingly,the intensity of spin-down fluctuations was found to positively correlate with increasing pulsar spin-down rates,and only a marginal dependence on spin frequency was noted by the researchers.These findings have significant implications for ongoing gravitational wave searches through ensemble timing of millisecond pulsars.They also shed light on the challenges associated with explaining the physical origins behind quasi-periodic and transient variations observed in a subset of these variable pulsars. Overall,this comprehensive study provides valuable insights into the dynamic nature of pulsar behavior,and highlights the need for further research to fully understand these intriguing astronomical phenomena.