Evidence for strong extragalactic magnetic fields from Fermi observations of TeV blazars
read the original abstract
Magnetic fields in galaxies are produced via the amplification of seed magnetic fields of unknown nature. The seed fields, which might exist in their initial form in the intergalactic medium, were never detected. We report a lower bound $B\ge 3\times 10^{-16}$~gauss on the strength of intergalactic magnetic fields, which stems from the nonobservation of GeV gamma-ray emission from electromagnetic cascade initiated by tera-electron volt gamma-ray in intergalactic medium. The bound improves as $\lambda_B^{-1/2}$ if magnetic field correlation length, $\lambda_B$, is much smaller than a megaparsec. This lower bound constrains models for the origin of cosmic magnetic fields.
This paper has not been read by Pith yet.
Forward citations
Cited by 11 Pith papers
-
Energy spectrum of magnetic fields from electroweak symmetry breaking
An analytic energy spectrum for magnetic fields from electroweak symmetry breaking is obtained from random inhomogeneous Higgs configurations and validated with continuous-field simulations.
-
Self-Consistent Parker Bound on Magnetic Monopoles
A self-consistent Parker bound on magnetic monopoles is derived using the galactic mean-field dynamo eigenmode and turbulent field seeding and acceleration, producing modified flux limits at low and intermediate masse...
-
JWST Constraints on Primordial Magnetic Fields
JWST UV luminosity function calibration of reionization history bounds primordial magnetic fields to √<B²> < 0.27 nG (n_B=-2) and < 0.18 nG (n_B=2) at 95% CL by ruling out double reionization at z≈24.
-
Revisiting constraints on primordial vector modes and implications for sourced magnetic fields and observed $EB$ power spectrum
Updated constraints on neutrino-sustained primordial vector modes imply magnetic fields too weak to seed observations and cannot reproduce the EB power spectrum while satisfying parity-even limits.
-
Primordial Magnetogenesis and Gravitational Waves from ALP-assisted Phase Transition
ALP-assisted first-order phase transitions can explain observed intergalactic magnetic fields and produce detectable gravitational waves, linking cosmology with particle physics searches.
-
Suppressed Magnetogenesis from Ultralight Dark Matter due to Finite Conductivity
Finite conductivity of the plasma suppresses parametric resonance amplification of electromagnetic fields from ultralight pseudoscalar dark matter, making it impossible to generate magnetic fields of sufficient streng...
-
Revisiting constraints on magnetogenesis from baryon asymmetry
Maximally helical primordial U(1)_Y magnetic fields can generate both intergalactic magnetic fields and baryon asymmetry; non-helical fields may work if Higgs dynamics compensate helicity loss to ≲10^{-9-10} precision...
-
Primordial black holes and magnetic fields in conformal neutrino mass models
Conformal U(1)' seesaw models produce PBHs contributing to dark matter and helical magnetic fields at seesaw scales of 10^4-10^11 GeV, with observable GW, microlensing, and Hawking signals at LISA, Roman, and future g...
-
Primordial magnetic fields in the light of upcoming post-EoR Lyman-$\alpha$ and 21-cm observations
Forecasts show DESI-like and SKA1-Mid observations could constrain primordial magnetic field amplitude and spectral index to roughly 10% precision via 21cm auto-spectrum and Lyα-21cm cross-spectrum.
-
Study of Flat Spectrum Radio Quasars and BL Lacertae Objects as Sources of Diffusive Ultra High-Energy Cosmic Rays
BL Lacs remain consistent with UHECR observations while FSRQs are disfavoured by anisotropy and source density mismatches after propagation modeling.
-
On the contribution of galaxies to the magnetic field in cosmic voids
Superposition of static galactic magnetic dipoles is screened by intergalactic plasma and cannot account for lower bounds on magnetic fields in cosmic voids from blazar gamma-ray data.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.