Limiting magnetic fields in the cosmic web with diffuse radio emission

作者：Brown, S.^*; Vernstrom, T.^*; Carretti, E.; Dolag, K.; Gaensler, B. M.; Staveley-Smith, L.; Bernardi, G.; Haverkorn, M.; Kesteven, M.; Poppi, S.

来源：Monthly Notices of the Royal Astronomical Society, 2017, 468(4): 4246-4253.

DOI：10.1093/mnras/stx746

• magnetic fields
• plasmas
• galaxies: clusters: intracluster medium
• intergalactic medium
• large-scale structure of Universe
• radio continuum: general

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.

• 出版日期2017-7