New constraints on the magnetization of the cosmic web using LOFAR Faraday rotation observations - Université Paris Cité Accéder directement au contenu
Article Dans Une Revue Monthly Notices of the Royal Astronomical Society Année : 2020

New constraints on the magnetization of the cosmic web using LOFAR Faraday rotation observations

S.P. O'Sullivan
  • Fonction : Auteur
M. Brüggen
  • Fonction : Auteur
F. Vazza
  • Fonction : Auteur
E. Carretti
  • Fonction : Auteur
N. Locatelli
  • Fonction : Auteur
C. Stuardi
  • Fonction : Auteur
V. Vacca
T. Vernstrom
  • Fonction : Auteur
G. Heald
  • Fonction : Auteur
C. Horellou
T.W. Shimwell
  • Fonction : Auteur
M.J. Hardcastle
  • Fonction : Auteur
H. Röttgering

Résumé

Measuring the properties of extragalactic magnetic fields through the effect of Faraday rotation provides a means to understand the origin and evolution of cosmic magnetism. Here, we use data from the LOFAR Two-Metre Sky Survey (LoTSS) to calculate the Faraday rotation measure (RM) of close pairs of extragalactic radio sources. By considering the RM difference (ΔRM) between physical pairs (e.g. double-lobed radio galaxies) and non-physical pairs (i.e. close projected sources on the sky), we statistically isolate the contribution of extragalactic magnetic fields to ΔRM along the line of sight between non-physical pairs. From our analysis, we find no significant difference between the ΔRM distributions of the physical and non-physical pairs, limiting the excess Faraday rotation contribution to <1.9 rad m^−2 (⁠|${\sim}95{{\ \rm per\ cent}}$| confidence). We use this limit with a simple model of an inhomogeneous universe to place an upper limit of 4 nG on the cosmological co-moving magnetic field strength on Mpc scales. We also compare the RM data with a more realistic suite of cosmological magnetohydrodynamical simulations that explore different magnetogenesis scenarios. Both magnetization of the large-scale structure by astrophysical processes such as galactic and AGN outflows, and simple primordial scenarios with seed magnetic field strengths <0.5 nG cannot be rejected by the current data; while stronger primordial fields or models with dynamo amplification in filaments are disfavoured.

Dates et versions

hal-02504656 , version 1 (10-03-2020)

Identifiants

Citer

S.P. O'Sullivan, M. Brüggen, F. Vazza, E. Carretti, N. Locatelli, et al.. New constraints on the magnetization of the cosmic web using LOFAR Faraday rotation observations. Monthly Notices of the Royal Astronomical Society, 2020, 495 (3), pp.2607-2619. ⟨10.1093/mnras/staa1395⟩. ⟨hal-02504656⟩
29 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More