The Second Radio Synchrotron Background Workshop: Conference Summary and Report

Abstract

We summarize the second radio synchrotron background workshop, which took place June 15-17, 2022 in Barolo, Italy. This meeting was convened because available measurements of the diffuse radio zero level continue to suggest that it is several times higher than can be attributed to known Galactic and extragalactic sources and processes, rendering it the least well understood electromagnetic background at present and a major outstanding question in astrophysics. The workshop agreed on the next priorities for investigations of this phenomenon, which include searching for evidence of the Radio Sunyaev-Zel'dovich effect, carrying out cross-correlation analyses of radio emission with other tracers, and supporting the completion of the 310 MHz absolutely calibrated sky map project.

arXiv comment34 pages, 19 figures, 3 tables, accepted to PASP, updated to in press version

References in corpus (202)

• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• LOFAR: The LOw-Frequency ARray
• Halo Models of Large Scale Structure
• The Cosmic Microwave Background Spectrum from the Full COBE/FIRAS Data Set
• Planck 2018 results. I. Overview and the cosmological legacy of Planck
• The Simons Observatory: Science goals and forecasts
• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• An absorption profile centred at 78 megahertz in the sky-averaged spectrum
• Enzo: An Adaptive Mesh Refinement Code for Astrophysics
• The GMRT 150 MHz All-sky Radio Survey: First Alternative Data Release TGSS ADR1
• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• Precise Relic WIMP Abundance and its Impact on Searches for Dark Matter Annihilation
• Planck 2018 results. VIII. Gravitational lensing
• The Primordial Inflation Explorer (PIXIE): A Nulling Polarimeter for Cosmic Microwave Background Observations
• The LOFAR Two-metre Sky Survey - I. Survey Description and Preliminary Data Release
• A New Model of the Galactic Magnetic Field
• Self-Consistent Models of the AGN and Black Hole Populations: Duty Cycles, Accretion Rates, and the Mean Radiative Efficiency
• Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
• Planck 2018 results. IV. Diffuse component separation
• Radio observational constraints on Galactic 3D-emission models
• The evolution of CMB spectral distortions in the early Universe
• The VLA-COSMOS 3 GHz Large Project: Continuum data and source catalog release
• The Structure of the Local Interstellar Medium V: Electron Densities
• A semi-empirical simulation of the extragalactic radio continuum sky for next generation radio telescopes
• ARCADE 2 Measurement of the Extra-Galactic Sky Temperature at 3-90 GHz
• Measurement of 21 cm brightness fluctuations at z ~ 0.8 in cross-correlation
• The Galactic Magnetic Field
• Late-time cosmology with 21cm intensity mapping experiments
• 3D maps of the local ISM from inversion of individual color excess measurements
• Improved upper limits on the 21-cm signal power spectrum of neutral hydrogen at $\mathbf{z}\approx 9.1$ from LOFAR
• Cosmology with Phase 1 of the Square Kilometre Array; Red Book 2018: Technical specifications and performance forecasts
• Australian Square Kilometre Array Pathfinder: I. System Description
• Deriving global structure of the Galactic Magnetic Field from Faraday Rotation Measures of extragalactic sources
• Upper limits on the 21-cm Epoch of Reionization power spectrum from one night with LOFAR
• Magnetic Fields and Faraday Rotation in Clusters of Galaxies
• Determination of z~0.8 neutral hydrogen fluctuations using the 21 cm intensity mapping auto-correlation
• An improved map of the Galactic Faraday sky
• Science With The Australian Square Kilometre Array Pathfinder
• The far-infrared/radio correlation as probed by Herschel
• Enhanced global signal of neutral hydrogen due to excess radiation at cosmic dawn
• Concerns about Modelling of the EDGES Data
• Resolving the Radio Source Background: Deeper Understanding Through Confusion
• Planck Early Results XVIII: The power spectrum of cosmic infrared background anisotropies
• Deep multi-redshift limits on Epoch of Reionisation 21cm Power Spectra from Four Seasons of Murchison Widefield Array Observations
• A measurement of secondary cosmic microwave background anisotropies from the 2500-square-degree SPT-SZ survey
• PRISM (Polarized Radiation Imaging and Spectroscopy Mission): An Extended White Paper
• Star formation near the Sun is driven by expansion of the Local Bubble
• Modeling the Radio Background from the First Black Holes at Cosmic Dawn: Implications for the 21 cm Absorption Amplitude
• Inverse cascade in decaying 3D magnetohydrodynamic turbulence
• The observable signature of late heating of the Universe during cosmic reionization
• First Results from HERA Phase I: Upper Limits on the Epoch of Reionization 21 cm Power Spectrum
• Signature of Excess Radio Background in the 21-cm Global Signal and Power Spectrum
• Primordial Black Holes as Dark Matter Candidates
• The Rapid ASKAP Continuum Survey Paper II: First Stokes I Source Catalogue Data Release
• The far-infrared/radio correlation and radio spectral index of galaxies in the SFR-M* plane up to z 2
• An absolutely calibrated survey of polarized emission from the northern sky at 1.4 GHz
• Coaxing Cosmic 21cm Fluctuations from the Polarized Sky using m-mode Analysis
• What does the first highly-redshifted 21-cm detection tell us about early galaxies?
• Design and characterization of the Large-Aperture Experiment to Detect the Dark Age (LEDA) radiometer systems
• Nonhelical inverse transfer of a decaying turbulent magnetic field
• BLAST: the far-infrared/radio correlation in distant galaxies
• New Physics in the Rayleigh-Jeans Tail of the CMB
• LiteBIRD: JAXA's new strategic L-class mission for all-sky surveys of cosmic microwave background polarization
• All-sky Galactic radiation at 45 MHz and spectral index between 45 and 408 MHz
• The nature of the Diffuse Gamma-Ray Background
• The Tiered Radio Extragalactic Continuum Simulation (T-RECS)
• The MeerKAT Galaxy Cluster Legacy Survey I. Survey Overview and Highlights
• Simplified Models of Mixed Dark Matter
• The Radio Background Below 100 MHz
• The redshifted 21-cm signal in the EDGES low-band spectrum
• Empirical Covariance Modeling for 21 cm Power Spectrum Estimation: A Method Demonstration and New Limits from Early Murchison Widefield Array 128-Tile Data
• Bayesian constraints on the global 21-cm signal from the Cosmic Dawn
• Spectral Index of the Diffuse Radio Background Measured From 100 to 200 MHz
• The Rise of the First Stars: Supersonic Streaming, Radiative Feedback, and 21-cm Cosmology
• Foregrounds for observations of the cosmological 21 cm line: II. Westerbork observations of the fields around 3C196 and the North Celestial Pole
• Constraining primordial black holes as dark matter using the global 21-cm signal with X-ray heating and excess radio background
• Dark Photon Oscillations in Our Inhomogeneous Universe
• Anisotropies in the diffuse gamma-ray background measured by the Fermi LAT
• The History and Future of the Local and Loop I Bubbles
• Beyond y and μ: the shape of the CMB spectral distortions in the intermediate epoch, 1.5x10^4 < z < 2x10^5
• First Limits on the 21 cm Power Spectrum during the Epoch of X-ray heating
• The Galactic halo magnetic field revisited
• The Australian Square Kilometre Array Pathfinder: System Architecture and Specifications of the Boolardy Engineering Test Array
• HI intensity mapping with MeerKAT: power spectrum detection in cross-correlation with WiggleZ galaxies
• HI constraints from the cross-correlation of eBOSS galaxies and Green Bank Telescope intensity maps
• Cosmological AMR MHD with Enzo
• SARAS 2 constraints on global 21-cm signals from the Epoch of Reionization
• A 189 MHz, 2400 square degree polarization survey with the Murchison Widefield Array 32-element prototype
• Green's function of the cosmological thermalization problem
• The LWA1 Low Frequency Sky Survey
• Confirmation of Wide-Field Signatures in Redshifted 21 cm Power Spectra
• Signals From the Epoch of Cosmological Recombination
• Anomalies in Physical Cosmology
• Foreground Model and Antenna Calibration Errors in the Measurement of the Sky-Averaged λ21 cm Signal at z~20
• Radio Galaxy populations and the multi-tracer technique: pushing the limits on primordial non-Gaussianity
• Polarised radio filaments outside the Galactic plane
• Modeling the magnetized Local Bubble from dust data
• Tight Constraints on the Excess Radio Background at $z=9.1$ from LOFAR
• Sub-arcsecond imaging with the International LOFAR Telescope I. Foundational calibration strategy and pipeline
• Green's function of the cosmological thermalization problem II: effect of photon injection and constraints
• High-redshift radio galaxies: a potential new source of 21-cm fluctuations
• ARCADE 2 Observations of Galactic Radio Emission
• S-band Polarization All Sky Survey (S-PASS): survey description and maps
• Heating of the intergalactic medium by the cosmic microwave background during cosmic dawn
• Deep 3 GHz Number Counts from a P(D) Fluctuation Analysis
• The subtlety of Ly-a photons: changing the expected range of the 21-cm signal
• The contribution of the Unresolved Extragalactic Radio Sources to the Brightness Temperature of the sky
• HI intensity mapping with MeerKAT: Calibration pipeline for multi-dish autocorrelation observations
• A dark matter interpretation for the ARCADE excess?
• Spectral distortion constraints on photon injection from low-mass decaying particles
• Improved Measurement of the Spectral Index of the Diffuse Radio Background Between 90 and 190 MHz
• Fast simulations for intensity mapping experiments
• SKAO HI Intensity Mapping: Blind Foreground Subtraction Challenge
• The black hole fundamental plane from a uniform sample of radio and X-ray emitting broad line AGNs
• Sources of the Radio Background Considered
• Joint Planck and WMAP CMB Map Reconstruction
• Low Frequency Radio Constraints on the Synchrotron Cosmic Web
• A LOFAR study of non-merging massive galaxy clusters
• Exploring the high-redshift PBH-$\Lambda$CDM Universe: early black hole seeding, the first stars and cosmic radiation backgrounds
• A wide-band, active antenna system for long wavelength radio astronomy
• Is there an unaccounted excess Extragalactic Cosmic Radio Background?
• Recovery of 21 cm intensity maps with sparse component separation
• Illuminating the dark ages: Cosmic backgrounds from accretion onto primordial black hole dark matter
• The Local Bubble: a magnetic veil to our Galaxy
• The BINGO Project I: Baryon Acoustic Oscillations from Integrated Neutral Gas Observations
• The ARCADE 2 Instrument
• Charting the Interstellar Magnetic Field causing the Interstellar Boundary Explorer (IBEX) Ribbon of Energetic Neutral Atoms
• Spectral Index of the Diffuse Radio Background Between 50 and 100 MHz
• Dark Stars: a new look at the First Stars in the Universe
• The C-Band All-Sky Survey (C-BASS): Design and capabilities
• The 154 MHz radio sky observed by the Murchison Widefield Array: noise, confusion and first source count analyses
• CosmoSpec: Fast and detailed computation of the cosmological recombination radiation from hydrogen and helium
• The faint radio sky: VLBA observations of the COSMOS field
• Feedback by massive stars and the emergence of superbubbles II. X-ray properties
• Lyman-$\alpha$ coupling and heating at Cosmic Dawn
• Limits on Foreground Subtraction from Chromatic Beam Effects in Global Redshifted 21 cm Measurements
• Contribution to the Diffuse Radio Background from Extragalactic Radio Sources
• A 21-cm power spectrum at 48 MHz, using the Owens Valley Long Wavelength Array
• The Radio Synchrotron Background: Conference Summary and Report
• Isotropic Radio Background from Quark Nugget Dark Matter
• Deep sub-arcsecond widefield imaging of the Lockman Hole field at 144 MHz
• Practical Modeling of Large-Scale Galactic Magnetic Fields: Status and Prospects
• Early Science from POSSUM: Shocks, turbulence, and a massive new reservoir of ionised gas in the Fornax cluster
• The interface between the outer heliosphere and the inner lism: Morphology of the local interstellar cloud, its hydrogen hole, stromgren shells, and ${}^{60}$Fe accretion
• The contribution of discrete sources to the sky temperature at 144 MHz
• Improved 21 cm Epoch Of Reionization Power Spectrum Measurements with a Hybrid Foreground Subtraction and Avoidance Technique
• Breaks in interstellar spectra of positrons and electrons derived from time-dependent AMS data
• The isotropic radio background revisited
• The clustering of radio galaxies: biasing and evolution versus stellar mass
• GeV-TeV Cosmic Ray Leptons in the Solar System from the Bow Shock Wind Nebula of the Nearest Millisecond Pulsar J0437-4715
• The e-MERLIN Galaxy Evolution Survey (e-MERGE): Overview and Survey Description
• Unresolved Gamma-Ray Sky through its Angular Power Spectrum
• The Long Wavelength Array Software Library
• Cosmic Star-Formation History Measured at 1.4 GHz
• Cross-correlating radio continuum surveys and CMB lensing: constraining redshift distributions, galaxy bias and cosmology
• Cosmic backgrounds due to the formation of the first generation of supermassive black holes
• Background of radio photons from primordial black holes
• Using the cosmological recombination radiation to probe early dark energy and fundamental constant variations
• Foreground modelling via Gaussian process regression: an application to HERA data
• The ASKAP-EMU Early Science Project:Radio Continuum Survey of the Small Magellanic Cloud
• A novel method for component separation of extended sources in X-ray astronomy
• Evaluating the Morphology of the Local Interstellar Medium: Using New Data to Distinguish Between Multiple Discrete Clouds and a Continuous Medium
• The non-thermal superbubble in IC 10: the generation of cosmic ray electrons caught in the act
• Eddington ratio and accretion efficiency in AGN evolution
• Spectral index of the Galactic foreground emission in the 50-87 MHz range
• Absolute Calibration of Diffuse Radio Surveys at 45 and 150 MHz
• The unusual smoothness of the extragalactic unresolved radio background
• Undiscovered pulsar in the Local Bubble as an explanation of the local high energy cosmic ray all-electron spectrum
• A Map of Diffuse Radio Emission at 182 MHz to Enhance Epoch of Reionization Observations in the Southern Hemisphere
• Cluster Mergers and the Origin of the ARCADE-2 Excess
• The large scale clustering of radio sources
• Sensitivity forecasts for the cosmological recombination radiation in the presence of foregrounds
• Constraint on Primordial Magnetic Fields In the Light of ARCADE 2 and EDGES Observations
• The contribution of ultracompact dark matter minihalos to the isotropic radio background
• Lower Limits on the Anisotropy of the Extragalactic Gamma-Ray Background implied by the 2FGL and 1FHL Catalogs
• Updated galactic radio constraints on Dark Matter
• Using the Sun to Measure the Primary Beam Response of the Canadian Hydrogen Intensity Mapping Experiment
• A Way Out of the Bubble Trouble? - Upon Reconstructing the Origin of the Local Bubble and Loop I via Radioisotopic Signatures on Earth
• Polarized Synchrotron Foreground Assessment for CMB Experiments
• Refined modelling of the radio SZ signal: kinematic terms, relativistic temperature corrections and anisotropies in the radio background
• Decaying turbulence and magnetic fields in galaxy clusters
• Far beyond stacking: Fully bayesian constraints on sub-microJy radio source populations over the XMM-LSS-VIDEO field
• Synergies across the spectrum for particle dark matter indirect detection: how HI intensity mapping meets gamma rays
• Investigating the Contribution of Extended Radio Sources to the Epoch of Reionisation Power Spectrum
• A Circularly Symmetric Antenna Design With High Polarization Purity and Low Spillover
• Measurement of the Anisotropy Power Spectrum of the Radio Synchrotron Background
• Can Planck constrain indirect detection of dark matter in our galaxy?
• Dark matter implications of the WMAP-Planck Haze
• SKA-Low Intensity Mapping Pathfinder Updates: Deeper 21 cm Power Spectrum Limits from Improved Analysis Frameworks
• The Anisotropy of the Extragalactic Radio Background from Dark Matter Annihilation
• Axial Ratio of Edge-On Spiral Galaxies as a Test For Extended Bright Radio Halos
• The contribution of star-forming galaxies to the cosmic radio background
• Can the Local Bubble explain the radio background?
• Black holes at cosmic dawn in the redshifted 21cm signal of HI
• Are Active Galactic Nuclei the Solution to the Excess Cosmic Radio Background at 1.4 GHz?
• Microwave and radio emission of dusty star-forming galaxies: Implication for the cosmic radio background
• Excess in the High Frequency Radio Background: Insights from Planck
• Importance of intracluster scattering and relativistic corrections from tSZ effect with Cosmic Infrared Background
• Dark Matter constraints from Planck observations of the Galactic polarized synchrotron emission
• Some Implications of the Leptonic Annihilation of Dark Matter: Possible Galactic Radio Emission Signatures and the Excess Radio Flux of Extragalactic Origin
• A Comprehensive Bayesian re-analysis of the SARAS2 data from the Epoch of Reionization
• Clustering properties of TGSS radio sources

Cited by in corpus (17)

• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• RHINO: A large horn antenna for detecting the 21cm global signal
• Relic neutrino decay solution to the excess radio background
• Impact of extragalactic point sources on the low-frequency sky spectrum and cosmic dawn global 21-cm measurements
• Radiative transfer of Lyman-$\alpha$ photons at cosmic dawn with realistic gas physics
• Diffuse Sources, Clustering and the Excess Anisotropy of the Radio Synchrotron Background
• Bayesian evidence for flux scale errors in Galactic synchrotron maps
• Uncertainties of the 30-408 MHz Galactic emission as a calibration source for radio detectors in astroparticle physics
• L-BASS: a project to produce an absolutely calibrated 1.4 GHz sky map, I -- Scientific rationale and system overview
• ECHO21: a tool for modelling global 21-cm signal from dark ages to reionization
• An Instrument Error Budget for Space-Based Absolute Flux Measurements of the Sky Synchrotron Spectrum Below 20 MHz
• Increase in the Brightness of the Cosmic Radio Background toward Galaxy Clusters
• A Hierarchical Shock Model of Ultra-High-Energy Cosmic Rays
• Polarized synchrotron data and the structure of the Galactic magnetic field
• Disentangling the anisotropic radio sky: Fisher forecasts for 21cm arrays
• Classification of Radio Backgrounds at Cosmic Dawn and 21 cm Signal Confirmation Using Neural Networks
• Axion-Like Particle Dark Matter Intensity Mapping: A New Probe via Cross-Correlation with Galaxy Surveys