Limiting magnetic fields in the cosmic web with diffuse radio emission
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 3σ 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) μG in filaments at the current epoch and a limit on the primordial magnetic field (PMF) of BPMF < 1.0 nG.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 2017
- DOI:
- 10.1093/mnras/stx746
- arXiv:
- arXiv:1703.07829
- Bibcode:
- 2017MNRAS.468.4246B
- Keywords:
-
- magnetic fields;
- plasmas;
- galaxies: clusters: intracluster medium;
- intergalactic medium;
- large-scale structure of Universe;
- radio continuum: general;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 9 pages, 6 figures, accepted to MNRAS