Stacking the Synchrotron Cosmic Web with FIGARO
arXiv:2108.13682 · doi:10.1017/pasa.2022.26
Abstract
Recently Vernstrom et al. (2021) claimed the first definitive detection of the synchrotron cosmic web, obtained by `stacking' hundreds of thousands of pairs of close-proximity clusters in low-frequency radio observations and looking for a residual excess signal spanning the intracluster bridge. A reproduction study by Hodgson et al. (2022), using both the original radio data as well as new observations with the Murchison Widefield Array, failed to confirm these findings. Whilst the detection remains unsure, we here turn to stacking a simulated radio sky to understand what kind of excess radio signal is predicted by our current best cosmological models of the synchrotron cosmic web. We use the FIlaments & GAlactic RadiO (Hodgson et al., 2021a) simulation, which models both the synchrotron cosmic web as well as various subtypes of active galactic nucleii and star forming galaxies. Being a simulation, we have perfect knowledge of the location of clusters and galaxy groups which we use in our own stacking experiment. Whilst we do find an excess radio signature in our stacks that is attributable to the synchrotron cosmic web, its distribution is very different to that found by Vernstrom et al. (2021). Instead, we observe the appearance of excess emission on the immediate interiors of cluster pairs as a result of asymmetric, `radio relic'-like shocks surrounding cluster cores, whilst the excess emission spanning the intracluster region -- attributable to filaments proper -- is two orders of magnitude lower and undetectable in our experiment even under ideal conditions.
arXiv commentAccepted by Publications of the Astronomical Society of Australia. Revision 2 submitted after changes from peer review: focus of paper shifted to results of FIGARO only, ignoring potential sources of contamination in Vernstrom et al. (2021), such a radio halos, PSF sidelobes, etc
References in corpus (35)
- The Murchison Widefield Array: the Square Kilometre Array Precursor at low radio frequencies
- Where are the Baryons?
- Baryons in the Warm-Hot Intergalactic Medium
- A census of baryons in the Universe from localized fast radio bursts
- GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue
- GLEAM: The GaLactic and Extragalactic All-sky MWA survey
- Observations of the MIssing Baryons in the warm-hot intergalactic medium
- Radio signature of cosmological structure formation shocks
- Warm-hot baryons comprise 5-10 per cent of filaments in the cosmic web
- New limits on extragalactic magnetic fields from rotation measures
- A radio ridge connecting two galaxy clusters in a filament of the cosmic web
- Probing the missing baryons with the Sunyaev-Zel'dovich effect from filaments
- Magnetic field evolution in relativistic unmagnetized collisionless shocks
- The Tiered Radio Extragalactic Continuum Simulation (T-RECS)
- Second order Fermi reacceleration mechanisms and large scale synchrotron radio emission in intra-cluster bridges
- The Radio Sky at Meter Wavelengths: m-Mode Analysis Imaging with the Owens Valley Long Wavelength Array
- New constraints on the magnetization of the cosmic web using LOFAR Faraday rotation observations
- First detection of stacked X-ray emission from cosmic web filaments
- Differences in Faraday Rotation Between Adjacent Extragalactic Radio Sources as a Probe of Cosmic Magnetic Fields
- Forecasts for the detection of the magnetised cosmic web from cosmological simulations
- The 2dF Galaxy Redshift Survey: Hierarchical galaxy clustering
- The intergalactic magnetic field probed by a giant radio galaxy
- Low Frequency Radio Constraints on the Synchrotron Cosmic Web
- How many radio relics await discovery?
- Magnetic field strength in cosmic web filaments
- Limiting Magnetic Fields in the Cosmic Web with Diffuse Radio Emission
- Detecting shocked intergalactic gas with X-ray and radio observations
- Detection of intercluster gas in superclusters using the thermal Sunyaev-Zel'dovich effect
- Empirical Photometric Redshifts of Luminous Red Galaxies and Clusters in SDSS
- Radio Emission in the Cosmic Web
- Simulations and observational tests of primordial magnetic fields from Cosmic Microwave Background constraints
- Synchrotron Emission on the Largest Scales: Radio Detection of the Cosmic-Web
- Ultra-Steep Spectrum Radio `Jellyfish' Uncovered in Abell 2877
- FIGARO Simulation: FIlaments & GAlactic RadiO Simulation
- Searching for the Synchrotron Cosmic Web Again: A replication attempt