Probing the Cosmological Principle in the counts of radio galaxies at different frequencies

Understand

According to the Cosmological Principle, the matter distribution on very large scales should have a kinematic dipole that is aligned with that of the CMB.

• We determine the dipole anisotropy in the number counts of two all-sky surveys of radio galaxies.
• For the first time, this analysis is presented for the TGSS survey, allowing us to check consistency of the radio dipole at low and high frequencies by comparing the results with the well-known NVSS survey.
• We match the flux thresholds of the catalogues, with flux limits chosen to minimise systematics, and adopt a strict masking scheme.