Speaker
Description
A novel secondary CMB anisotropy, the non-thermal Sunyaev-Zel’dovich (nthSZ) distortions of the CMB sourced by radio galaxies, opens up a new window to radio-galaxy physics and cosmology. We show how relativistic, non-thermal electrons in radio galaxy lobes imprint distinctive signatures on the cosmic microwave background via the non-thermal Sunyaev–Zel’dovich (nthSZ) effect, using a physically grounded model that avoids uncertain extrapolations of the electron spectrum. Extending this to a cosmological population, we show that while the mean distortion remains within current observational bounds, its unique spectral shape makes it a compelling target for upcoming multi-frequency CMB experiments. This positions the ntSZ effect as both a subtle systematic (for upcoming spectral distortion experiments) and an exciting new probe: it opens a new gateway into the low-energy relativistic electron population, jet energetics, and the connection between black holes and their cosmological implications. Finally, we propose a new and promising, distance-ladder independent, probe of the cosmic expansion using the nthSZ distortions.