A numerical model of resistive generation of intergalactic magnetic field at cosmic dawn

Дата и время публикации : 2011-10-18T20:12:21Z

Авторы публикации и институты :
Francesco Miniati (ETHZ)
A. R. Bell (Oxford)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 6 pages, 2 Figs. To appear in the proceedings of the 6th Annual International Conference on Numerical Modeling of Space Plasma Flows in Valencia, Spain, 13-17 June, 2011 (ASTRONUM-2011)
Первичная категория: astro-ph.CO

Все категории : astro-ph.CO, astro-ph.HE

Краткий обзор статьи: Miniati and 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, $j_t$, and associated electric fields, $vec E=etavec j_t$ there. Because the resistivity, $eta$, 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 and 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.

Category: Physics