A Stimulating Explanation of the Extragalactic Radio Background

Abstract

Despite an intense theoretical and experimental effort over the past decade, observations of the extragalactic radio background at multiple frequencies below 10 GHz are not understood in terms of known radio sources, and may represent a sign of new physics. In this Letter we identify a new class of dark sector models with feebly interacting particles, where dark photons oscillate into ordinary photons that contribute to the radio background. Our scenario can explain both the magnitude and the spectral index of the radio background, while being consistent with other cosmological and astrophysical constraints. These models predict new relativistic degrees of freedom and spectral distortions of the cosmic microwave background, which could be detected in the next generation of experiments.

arXiv comment5+14 pages, 3+5 figures

References in corpus (78)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• The Cosmic Microwave Background Spectrum from the Full COBE/FIRAS Data Set
• The Temperature of the Cosmic Microwave Background
• An absorption profile centred at 78 megahertz in the sky-averaged spectrum
• The Primordial Inflation Explorer (PIXIE): A Nulling Polarimeter for Cosmic Microwave Background Observations
• Extended Limber Approximation
• Weak Lensing and Cosmology
• ARCADE 2 Measurement of the Extra-Galactic Sky Temperature at 3-90 GHz
• Improved upper limits on the 21-cm signal power spectrum of neutral hydrogen at $\mathbf{z}\approx 9.1$ from LOFAR
• Uncorrelated Modes of the Nonlinear Power Spectrum
• HyRec: A fast and highly accurate primordial hydrogen and helium recombination code
• Enhanced global signal of neutral hydrogen due to excess radiation at cosmic dawn
• Resolving the Radio Source Background: Deeper Understanding Through Confusion
• Dark Radiation constraints on minicharged particles in models with a hidden photon
• The Origin of the Extragalactic Gamma-Ray Background and Implications for Dark-Matter Annihilation
• Modeling the Radio Background from the First Black Holes at Cosmic Dawn: Implications for the 21 cm Absorption Amplitude
• Massive hidden photons as lukewarm dark matter
• A fresh look at linear cosmological constraints on a decaying dark matter component
• Signature of Excess Radio Background in the 21-cm Global Signal and Power Spectrum
• A new estimate of the extragalactic radio background and implications for ultra-high-energy gamma-ray propagation
• Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations
• What does the first highly-redshifted 21-cm detection tell us about early galaxies?
• Galactic synchrotron emission with cosmic ray propagation models
• The radio emission from the Galaxy at 22 MHz
• Probability Distribution Function of Cosmological Density Fluctuations from Gaussian Initial Condition: Comparison of One- and Two-point Log-normal Model Predictions with N-body Simulations
• New Physics in the Rayleigh-Jeans Tail of the CMB
• Microwave Background Constraints on Mixing of Photons with Hidden Photons
• A Determination of the Spectral Index of Galactic Synchrotron Emission in the 1-10 GHz range
• The Radio Background Below 100 MHz
• Bayesian constraints on the global 21-cm signal from the Cosmic Dawn
• Dark Photon Oscillations in Our Inhomogeneous Universe
• Detecting the Stimulated Decay of Axions at Radio Frequencies
• A model for the cosmological evolution of low frequency radio sources
• The contribution of the Unresolved Extragalactic Radio Sources to the Brightness Temperature of the sky
• A dark matter interpretation for the ARCADE excess?
• Spectral distortion constraints on photon injection from low-mass decaying particles
• Sources of the Radio Background Considered
• Is there an unaccounted excess Extragalactic Cosmic Radio Background?
• Particle dark matter searches in the anisotropic sky
• Deciphering Contributions to the Extragalactic Gamma-Ray Background from 2 GeV to 2 TeV
• The Radio Scream from Black Holes at Cosmic Dawn: A Semi-Analytic Model for the Impact of Radio Loud Black-Holes on the 21 cm Global Signal
• Dark Photon Dark Matter in the Presence of Inhomogeneous Structure
• Contribution to the Diffuse Radio Background from Extragalactic Radio Sources
• An Australia telescope survey for CMB anisotropies
• Updated constraints on decaying cold dark matter
• The Radio Synchrotron Background: Conference Summary and Report
• Modeling Dark Photon Oscillations in Our Inhomogeneous Universe
• Astrophysical radio background cannot explain the EDGES 21-cm signal: constraints from cooling of non-thermal electrons
• Effective photon mass and (dark) photon conversion in the inhomogeneous Universe
• The Isotropic Radio Background and Annihilating Dark Matter
• The contribution of discrete sources to the sky temperature at 144 MHz
• The isotropic radio background revisited
• Constraints on dark matter to dark radiation conversion in the late universe with DES-Y1 and external data
• How to suppress exponential growth -- on the parametric resonance of photons in an axion background
• Do you smell something decaying? Updated linear constraints on decaying dark matter scenarios
• The Deep Diffuse Extragalactic Radio Sky at 1.75 GHz
• Cosmic backgrounds due to the formation of the first generation of supermassive black holes
• Background of radio photons from primordial black holes
• The unusual smoothness of the extragalactic unresolved radio background
• Cluster Mergers and the Origin of the ARCADE-2 Excess
• All sky angular power spectrum: I. Estimating brightness temperature fluctuations using TGSS 150 MHz survey
• Constraining dark photons and their connection to 21 cm cosmology with CMB data
• Nested sampling with any prior you like
• An updated estimate of the cosmic radio background and implications for ultra-high-energy photon propagation
• Mapping the spectral index of Cas A: evidence for flattening from radio to infrared
• The Anisotropy of the Extragalactic Radio Background from Dark Matter Annihilation
• $t$-channel singularities in cosmology and particle physics
• Measurement of the Anisotropy Power Spectrum of the Radio Synchrotron Background
• Cosmological origin of anomalous radio background
• Axial Ratio of Edge-On Spiral Galaxies as a Test For Extended Bright Radio Halos
• Can the Local Bubble explain the radio background?
• A closer look at dark photon explanations of the excess radio background

Cited by in corpus (5)

• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Relic neutrino decay solution to the excess radio background
• Primordial black holes as dark matter candidates: Multi-frequency constraints from cosmic radiation backgrounds
• Probing self-interacting ultrahigh-energy neutrinos with the cosmic 21-cm signal
• Recovering 21cm Monopole Signals Without Smoothness