Cross-Survey Evidence for a Polar Radio Dipole

Andrew Morton · Public preprint · Exploratory observational analysis

Compares radio-source count dipoles across NVSS, TGSS and LoTSS, including flux dependence and diagnostic checks.

Current program context

Source note: the manuscript’s Figure 1 caption and comparison paragraph differ in their description of the LoTSS baseline. Quantitative significance and new-physics claims are not promoted on this site pending that check.

Abstract

We present a simple, fully reproducible counts–in–cells analysis of public radio surveys that yields a stable, high–latitude dipole in the surface density of extragalactic radio sources. Using NVSS (1.4 GHz), TGSS ADR1 (150 MHz), and a cross-check with LoTSS DR2 (144 MHz), we find directions that cluster near the north celestial pole with inter-survey agreement at the ∼20° level. At faint flux thresholds the measured dipole amplitude lies above or comparable to the kinematic expectation D_kin(x, α) from aberration and Doppler boosting, and approaches D_kin smoothly as the flux cut is brightened. LoTSS shows the same trend but with lower amplitude, consistent with deeper coverage and different completeness behavior. We derive the estimator from a Poisson map model, report jackknife uncertainties, and provide isotropy p–values from Poisson Monte Carlo. Diagnostic null tests (hemispherical asymmetry and patchwise clustering) return null results. All figures and tables are reproduced by a single notebook that queries VizieR directly.[1]

Abstract references

[1] Code and data for the radio-dipole paper

Scope

The reported pattern remains an exploratory observational result. Survey completeness, footprint, declination structure, source definitions and clustering are material alternatives to a new physical explanation.

Paper and supporting files

Code and data are deposited separately in the companion record linked below.

Read the current paper and supporting files on Zenodo