Evidence of X-ray emission from the Warm Hot Intergalactic Medium
Abstract
The Universe has evolved from an initial diffuse, uniform gas to a complex structure that includes both voids and high-density galaxy clusters connected by gaseous filaments, known as the Cosmic Web, and traced by 3D surveys of galaxies. The filamentary structure contains a significant fraction of the baryonic matter and is predicted to be mostly in the form of a moderately high temperature plasma, the Warm Hot Intergalactic Medium. Plasma at this temperature and ionization level emits mostly in soft X-rays. The filamentary structure, however, is hard to detect because the other sources contributing to the Diffuse X-ray Background are much brighter and, currently, there are very few reported detections of emission from the filaments. We report the first high-confidence level indirect detection of X-ray emission from the Warm Hot Intergalactic Medium. Applying the Power Spectrum Analysis to XMM-Newton and eROSITA data, we separated its contribution from other sources modeled in previous studies. Our result is in good agreement with numerical simulations and fills a critical gap in the picture of the large-scale structure of the Universe, in which filamentary gas, galaxies and dark matter interact and co-evolve.
Keywords
Cite
@article{arxiv.2307.14411,
title = {Evidence of X-ray emission from the Warm Hot Intergalactic Medium},
author = {Giulia Cerini and Nico Cappelluti and Massimiliano Galeazzi and Eugenio Ursino},
journal= {arXiv preprint arXiv:2307.14411},
year = {2023}
}
Comments
31 pages, 10 figures, submitted to Nature Astronomy