6533b830fe1ef96bd1297bba
RESEARCH PRODUCT
Cosmological origin of anomalous radio background
James M. ClineAaron C. Vincentsubject
Structure formationCosmology and Nongalactic Astrophysics (astro-ph.CO)Astrophysics::High Energy Astrophysical PhenomenaDark matterCosmic microwave backgroundCosmic background radiationFOS: Physical sciencesAstrophysicsElectronAstrophysics::Cosmology and Extragalactic Astrophysics01 natural sciencesParticle decayHigh Energy Physics - Phenomenology (hep-ph)0103 physical sciences010303 astronomy & astrophysicsPhysicsdark matter theory010308 nuclear & particles physicsFísicaAstronomy and AstrophysicsCosmology of Theories beyond the SMRedshiftCharged particleHigh Energy Physics - Phenomenologyextragalactic magnetic fieldsAstrophysics - Cosmology and Nongalactic Astrophysicsdescription
The ARCADE 2 collaboration has reported a significant excess in the isotropic radio background, whose homogeneity cannot be reconciled with clustered sources. This suggests a cosmological origin prior to structure formation. We investigate several potential mechanisms and show that injection of relativistic electrons through late decays of a metastable particle can give rise to the observed excess radio spectrum through synchrotron emission. However, constraints from the cosmic microwave background (CMB) anisotropy, on injection of charged particles and on the primordial magnetic field, present a challenge. The simplest scenario is with a greater than or similar to 9 GeV particle decaying into e(+)e(-) at a redshift of z similar to 5, in a magnetic field of similar to 5 μG, which exceeds the CMB B-field constraints, unless the field was generated after decoupling. Decays into exotic millicharged particles can alleviate this tension, if they emit synchroton radiation in conjunction with a sufficiently large background magnetic field of a dark U(1)' gauge field.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-10-09 |