We propose a new method to tomographically probe cosmic birefringence using radio galaxies. We show that the redshift evolution of the cosmic birefringence angle induced by a slow-rolling pseudoscalar field, which is a candidate for dynamical dark energy, is independent of the detailed model of the pseudoscalar field. This universal profile evolves predominantly at $z\lesssim 10$. In contrast, if the origin is a dark matter-like pseudoscalar field, the resulting birefringence angle tends to be negligible in the low-redshift regime. This new insight provides a strong motivation to independently test the cosmic birefringence using polarized astrophysical sources such as radio galaxies. We find that a sample size of $\mathcal{O}{10}^5–{10}^6$ is required to distinguish the profiles, which is within the scope of ongoing and upcoming radio surveys such as ASKAP or SKA.

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• Cosmic microwave background
• Cosmic strings & domain walls
• Cosmological constant
• Cosmological parameters
• Cosmology
• Dark energy
• Formation & evolution of stars & galaxies
• Radio, microwave, & sub-mm astronomy
• Active & peculiar galaxies
• Astrophysical jets
• Galactic nuclei & quasars
• Galaxies