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| Paper: |
Resistive Generation of Intergalactic Magnetic Field
at Cosmic Dawn |
| Volume: |
459, 6th International Conference of Numerical Modeling of Space Plasma Flows (ASTRONUM 2011) |
| Page: |
125 |
| Authors: |
Miniati, F.; Bell, A. R. |
| Abstract: |
Miniati & Bell (2011) proposed a mechanism for the generation of magnetic
seeds that is based the finite resistivity of the low temperature IGM in the high redshift universe.
In this model, cosmic-ray protons generated by the first generation of galaxies,
escape into the intergalactic medium carrying an electric current that induces
return currents, jt, and associated electric fields, E = ηjt there.
Because the resistivity, η, depends on the IGM temperature, which
is highly inhomogeneous due to adiabatic contraction and shocks produced by structure
formation, a non-vanishing curl of the electric field exists which sustains the growth of magnetic field.
In this contribution we have developed an approximate numerical model for this process
by implementing the source terms of the resistive mechanism in the cosmological code CHARM.
Our numerical estimates substantiate the earlier analysis in Miniati & Bell (2011)
which found magnetic seeds between 10–18 and 10–16 Gauss throughout
cosmic space at redshift z ∼ 6, consistent with conservative estimates of magnetic
fields in voids at z ∼ 0 from recent gamma-ray experiments. |
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