Polarized accretion shocks from the cosmic web
Abstract
On the largest scales, galaxies are pulled together by gravity to form clusters, which are connected by filaments making a web-like pattern. Radio emission is predicted from this cosmic web, which should originate from the strong accretion shocks around the cosmic structures. We present the first observational evidence that Fermi-type acceleration from strong shocks surrounding the filaments of the cosmic web, as well as in peripherals of low-mass clusters, is at work in the Universe. Using all-sky radio maps and stacking on clusters and filaments, we have detected the polarization signature of the synchrotron emission with polarization fractions >= 20%, which is best explained by the organization of local magnetic fields by strong shock waves both at the cluster peripheries and between clusters. Our interpretation is well supported by a detailed comparison with state-of-the-art cosmological simulations.
Cite
@article{arxiv.2302.08072,
title = {Polarized accretion shocks from the cosmic web},
author = {Tessa Vernstrom and Jennifer West and Franco Vazza and Denis Wittor and Christopher John Riseley and George Heald},
journal= {arXiv preprint arXiv:2302.08072},
year = {2023}
}
Comments
Published in Science Advances. Supplementary Materials available at https://www.science.org/doi/10.1126/sciadv.ade7233