An insight into chromatic behaviour of jitter in pulsars and its modelling: a case study of PSR J0437−4715

• DOI: 10.1093/mnras/stae041
• Publication Date: 2024-01-05T13:20:45Z
• Authors: A D Kulkarni; R M Shannon; D J Reardon; M T Miles; M Bailes; M Shamohammadi
• Keywords: 612; Astrophysics - High Energy Astrophysical Phenomena; Astrophysics - Instrumentation and Methods for Astrophysics

ABSTRACT Pulse-to-pulse profile shape variations introduce correlations in pulsar times of arrival across radio frequency measured at the same observational epoch. This leads to a broad-band noise excess radiometer noise, which is termed as pulse jitter noise. The presence limits achievable timing precision and decreases sensitivity data sets signals interest such nanohertz-frequency gravitational waves. Current white models used analyses attempt account for this, assuming complete correlation uncertainties through collected unique observation no dependence (which corresponds rank-one covariance matrix). However, previous studies show that brightest millisecond decimetre wavelengths, PSR J0437−4715, shows decorrelation Here, we present detailed study J0437−4715 implement new technique model it. We rate due can be expressed power law frequency. analyse matrix associated with process find higher rank approximation essential use this novel method significantly improves estimation other chromatic parameters dispersion measure variations. significant improvement errors suggesting current methods are not biased parameters, misspecification. energy similar indicating common origin both observables.