# Random Primordial Magnetic Fields and the Gas Content of Dark Matter Halos - Astrophysics > Cosmology and Nongalactic Astrophysics

Random Primordial Magnetic Fields and the Gas Content of Dark Matter Halos - Astrophysics > Cosmology and Nongalactic Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We recently predicted the existence of random primordial magnetic fieldsRPMF in the form of randomly oriented cells with dipole-like structure with acell size $L 0$ and an average magnetic field $B 0$. Here we investigate modelsfor primordial magnetic field with a similar web-like structure, and othergeometries, differing perhaps in $L 0$ and $B 0$. The effect of RPMF on theformation of the first galaxies is investigated. The filtering mass, $M F$, isthe halo mass below which baryon accretion is severely depressed. We show thatthese RPMF could influence the formation of galaxies by altering the filteringmass and the baryon gas fraction of a halo, $f g$. The effect is particularlystrong in small galaxies. We find, for example, for a comoving $B 0=0.1\muG$,and a reionization epoch that starts at $z s=11$ and ends at $z e=8$, for$L 0=100\,\text{pc}$ at $z=12$, the $f g$ becomes severely depressed for$M<10^7\msun$, whereas for $B 0=0$ the $f g$ becomes severely depressed onlyfor much smaller masses, $M<10^5\msun$. We suggest that the observation of$M F$ and $f g$ at high redshifts can give information on the intensity andstructure of primordial magnetic fields.

Autor: Rafael S. de Souza, Luiz Felippe S. Rodrigues, Reuven Opher

Fuente: https://arxiv.org/