The SRG/eROSITA all-sky survey. X-ray emission from the warm-hot phase gas in long cosmic filaments

Abstract

The properties of the warm-hot intergalactic medium (WHIM) in cosmic filaments are among the least quantified units in modern astrophysics. The Spectrum Roentgen Gamma/eROSITA All Sky Survey ((SRG/eRASS) provides a unique opportunity to study the X-ray emission of the WHIM. We applied both imaging and spectroscopic stacking techniques to the data of the first four eRASS scans to inspect the X-ray emissions from 7817 cosmic filaments identified from Sloan Digital Sky Survey (SDSS) optical galaxy samples. We obtained a $9\sigma$ significant detection of the total X-ray signal from filaments in the 0.3--1.2~keV band. Here, we introduce a novel method to estimate the contamination fraction from unmasked X-ray halos, active galactic nuclei, and X-ray binaries associated with filament galaxies. We found an approximately 40\% contamination fraction for these unmasked sources, suggesting that the remaining 60\% of the signal could be coming from the WHIM and a $5.4\sigma$ detection significance of the WHIM. Moreover, we modeled the temperature and baryon density contrast of the detected WHIM by fitting the stacked spectrum and surface brightness profile. The best-fit temperature $\log (T/\mathrm{K})=6.84\pm 0.07$, obtained by using a single temperature model, is marginally higher than in the simulation results. This could be due to the fitting of a single temperature model on a multi-temperature spectrum. Assuming a 0.2 solar abundance, the best-fit baryon density contrast $\log {\Delta }_{\mathrm{b}}=1.88\pm 0.18$ is in general agreement with the X-ray emitting phases in the IllustrisTNG simulation. This result suggests that the broadband X-ray emission traces the high end of the temperature and density values that characterize the entire WHIM population.

15+8 pages, 11+7 figures, accepted for publication in A&A

References in corpus (40)

• K-corrections and filter transformations in the ultraviolet, optical, and near infrared
• HI4PI: A full-sky HI survey based on EBHIS and GASS
• The eROSITA X-ray telescope on SRG
• A census of baryons in the Universe from localized fast radio bursts
• PRIMUS: Constraints on Star Formation Quenching and Galaxy Merging, and the Evolution of the Stellar Mass Function From z=0-1
• The SRG/eROSITA all-sky survey: First X-ray catalogues and data release of the western Galactic hemisphere
• The eROSITA Final Equatorial Depth Survey (eFEDS): The X-ray catalog
• The close environments of accreting massive black holes are shaped by radiative feedback
• The Uchuu Simulations: Data Release 1 and Dark Matter Halo Concentrations
• A statistical test for Nested Sampling algorithms
• On the use of C-stat in testing models for X-ray spectra
• Detection of large-scale X-ray bubbles in the Milky Way halo
• Detection of hot gas in the filament connecting the clusters of galaxies Abell 222 and Abell 223
• Unifying X-ray Scaling Relations from Galaxies to Clusters
• The eROSITA Final Equatorial-Depth Survey (eFEDS): Catalog of galaxy clusters and groups
• X-ray Binary Luminosity Function Scaling Relations for Local Galaxies Based on Subgalactic Modeling
• Systematic comparison of photoionised plasma codes with application to spectroscopic studies of AGN in X-rays
• Properties of gas phases around cosmic filaments at z=0 in the Illustris-TNG simulation
• The Abell 3391/95 galaxy cluster system: A 15 Mpc intergalactic medium emission filament, a warm gas bridge, infalling matter clumps, and (re-) accelerated plasma discovered by combining SRG/eROSITA data with ASKAP/EMU and DECam data
• First detection of stacked X-ray emission from cosmic web filaments
• zeus: A Python implementation of Ensemble Slice Sampling for efficient Bayesian parameter inference
• An EAGLE view of the missing baryons
• Active Galactic Nuclei and their Large-scale Structure: an eROSITA mock catalogue
• Characterising filaments in the SDSS volume from the galaxy distribution
• The eROSITA Final Equatorial-Depth Survey (eFEDS): X-ray Properties and Scaling Relations of Galaxy Clusters and Groups
• Full-sky photon simulation of clusters and active galactic nuclei in the soft X-rays for eROSITA
• A Self-Calibrating Halo-Based Group Finder: Application to SDSS
• Finding the missing baryons in the intergalactic medium with localized fast radio bursts
• The Physical Origins of the Identified and Still Missing Components of the Warm-Hot Intergalactic Medium: Insights from Deep Surveys in the Field of Blazar 1ES1553+113
• Exploring the contamination of the DES-Y1 Cluster Sample with SPT-SZ selected clusters
• The hot circumgalactic medium in the eROSITA All-Sky Survey II. Scaling relations between X-ray luminosity and galaxies' mass
• An 8.0\% Determination of the Baryon Fraction in the Intergalactic Medium from Localized Fast Radio Bursts
• The cosmic web of X-ray active galactic nuclei seen through the eROSITA Final Equatorial Depth Survey (eFEDS)
• X-ray emission from cosmic web filaments in SRG/eROSITA data
• The challenge of measuring and mapping the missing baryons
• Monte Carlo Physarum Machine: Characteristics of Pattern Formation in Continuous Stochastic Transport Networks
• 1-DREAM: 1D Recovery, Extraction and Analysis of Manifolds in noisy environments
• The SRG/eROSITA All-Sky Survey: View of the Virgo Cluster
• Prospects of detecting soft X-ray emission from typical WHIM filaments around massive clusters and the Coma cluster soft excess
• Searching for the warm-hot intergalactic medium using XMM-Newton high-resolution X-ray spectra

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• The Average Soft X-ray Spectra of eROSITA Active Galactic Nuclei
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• The warm-hot intergalactic medium in inter-cluster filaments -- A forecast for HUBS observations based on eRASS1 superclusters
• Detection of pure warm-hot intergalactic medium emission from a $7.2$ Mpc long filament in the Shapley supercluster using X-ray spectroscopy
• Properties of the diffuse gas component in filaments detected in the Dianoga cosmological simulations
• The Three Hundred: Gas Properties Outside of Galaxy Cluster with the WHIM Contribution and Detection
• The SRG/eROSITA All-Sky Survey. Detection of shock-heated gas beyond the halo boundary into the accretion region
• X-ray emission in IllustrisTNG circum-cluster environments. II -- Possible origins of the soft X-ray excess emission