Random primordial magnetic fields and the gas content of dark matter haloes

Author(s)

de Souza, Rafael S. ^[1] ; Rodrigues, Luiz Felippe S. ^[1] ; Opher, Reuven ^[1]

Affiliation

^[1] Univ Sao Paulo, IAG, BR-05508900 Sao Paulo - Brazil

• Document type: Journal article
• Source: Monthly Notices of the Royal Astronomical Society; v. 410, n. 4, p. 2149-2155, FEB 2011.
• Web of Science Citations: 1

Abstract

We recently predicted the existence of random primordial magnetic fields (RPMFs) in the form of randomly oriented cells with dipole-like structure with a cell size L(0) and an average magnetic field B(0). Here, we investigate models for primordial magnetic field with a similar web-like structure, and other geometries, differing perhaps in L(0) and B(0). The effect of RPMF on the formation of the first galaxies is investigated. The filtering mass, M(F), is the halo mass below which baryon accretion is severely depressed. We show that these RPMF could influence the formation of galaxies by altering the filtering mass and the baryon gas fraction of a halo, f(g). The effect is particularly strong in small galaxies. We find, for example, for a comoving B(0) = 0.1 mu G, and a reionization epoch that starts at z(s) = 11 and ends at z(e) = 8, for L(0) = 100 pc at z = 12, the f(g) becomes severely depressed for M < 10(7) M(circle dot), whereas for B(0) = 0 the f(g) becomes severely depressed only for much smaller masses, M < 10(5) M(circle dot). We suggest that the observation of M(F) and f(g) at high redshifts can give information on the intensity and structure of primordial magnetic fields. (AU)

• FAPESP's process: 06/56213-9 - New physics from space: formation and evolution of structures in the universe
• Grantee: Claudia Lucia Mendes de Oliveira
• Support type: Research Projects - Thematic Grants