Observing the millimeter Universe with the NIKA2 camera

Relativistic SZ maps and electron temperature spectroscopy

28 Jun 2021, 14:55

30m

Speaker

Mathieu Remazeilles (University of Manchester)

Description

While third-generation CMB experiments have allowed to release the first maps of the Compton-$y$ distortion due to thermal Sunyaev-Zeldovich (SZ) effect, next-generation CMB experiments should allow to map also the electron gas temperature, $T_{\mathrm{e}}$, across the sky through the detection of relativistic corrections to the thermal SZ effect. We will discuss about the experimental requirements to break the $y$-$T_{\mathrm{e}}$ degeneracy of the observed SZ intensity, and propose a new component separation approach based on moment expansion to disentangle the $y$ and $T_{\mathrm{e}}$ observables of the relativistic SZ effect while mitigating foregrounds. We will show that this approach offers a new spectroscopic view of the galaxy clusters not only across frequencies but now also across temperatures. We will also show how the relativistic electron temperature power spectrum provides a new cosmological observable which could complement the Compton-$y$ map power spectrum to break some of the parameter degeneracies in future cosmological SZ analyses.

Presentation materials

Remazeilles_NIKA2_2021.pdf