Limiting magnetic fields in the cosmic web with diffuse radio emission

Brown, S.; Vernstrom, T.; Carretti, E.; Dolag, K.; Gänsler, B. M.; Staveley-Smith, L.; Bernardi, G.; Haverkorn, M.; Kesteven, M. und Poppi, S. (2017): Limiting magnetic fields in the cosmic web with diffuse radio emission. In: Monthly Notices of the Royal Astronomical Society, Bd. 468, Nr. 4: S. 4246-4253

Abstract

We set limits on the presence of the synchrotron cosmic web through the cross-correlation of the 2.3 GHz S-PASS survey with a model of the local cosmic web derived from constrained magnetohydrodynamic (MHD) simulations. The MHD simulation assumes cosmologically seeded magnetic fields amplified during large-scale structure formation and a population of relativistic electrons/positrons from proton-proton collisions within the intergalactic medium. We set a model-dependent 3 sigma upper limit on the synchrotron surface brightness of 0.16 mJy arcmin-2 at 2.3 GHz in filaments. Extrapolating from magnetic field maps created from the simulation, we infer an upper limit (density-weighted) magnetic field of 0.03 (0.13) mu G in filaments at the current epoch and a limit on the primordial magnetic field (PMF) of B-PMF < 1.0 nG.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0035-8711
• Sprache: Englisch