Bibcode
Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Arroja, F.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Ballardini, M.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chiang, H. C.; Chluba, J.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Diego, J. M.; Dolag, K.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Fergusson, J.; Finelli, F.; Florido, E.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G. et al.
Bibliographical reference
Astronomy and Astrophysics, Volume 594, id.A19, 27 pp.
Advertised on:
8
2016
Journal
Citations
375
Refereed citations
330
Description
We compute and investigate four types of imprint of a stochastic
background of primordial magnetic fields (PMFs) on the cosmic microwave
background (CMB) anisotropies: the impact of PMFs on the CMB temperature
and polarization spectra, which is related to their contribution to
cosmological perturbations; the effect on CMB polarization induced by
Faraday rotation; the impact of PMFs on the ionization history;
magnetically-induced non-Gaussianities and related non-zero bispectra;
and the magnetically-induced breaking of statistical isotropy. We
present constraints on the amplitude of PMFs that are derived from
different Planck data products, depending on the specific effect that is
being analysed. Overall, Planck data constrain the amplitude of PMFs to
less than a few nanoGauss, with different bounds that depend on the
considered model. In particular, individual limits coming from the
analysis of the CMB angular power spectra, using the Planck likelihood,
are B1 Mpc < 4.4 nG (where B1 Mpc is the
comoving field amplitude at a scale of 1 Mpc) at 95% confidence level,
assuming zero helicity. By considering the Planck likelihood, based only
on parity-even angular power spectra, we obtain B1 Mpc <
5.6 nG for a maximally helical field. For nearly scale-invariant PMFs we
obtain B1 Mpc < 2.0 nG and B1 Mpc < 0.9 nG
if the impact of PMFs on the ionization history of the Universe is
included in the analysis. From the analysis of magnetically-induced
non-Gaussianity, we obtain three different values, corresponding to
three applied methods, all below 5 nG. The constraint from the
magnetically-induced passive-tensor bispectrum is B1 Mpc <
2.8 nG. A search for preferred directions in the magnetically-induced
passive bispectrum yields B1 Mpc < 4.5 nG, whereas the
compensated-scalar bispectrum gives B1 Mpc < 3 nG. The
analysis of the Faraday rotation of CMB polarization by PMFs uses the
Planck power spectra in EE and BB at 70 GHz and gives B1 Mpc
< 1380 nG. In our final analysis, we consider the harmonic-space
correlations produced by Alfvén waves, finding no significant
evidence for the presence of these waves. Together, these results
comprise a comprehensive set of constraints on possible PMFs with Planck
data.