Ratio of E to B mode power for galactic foreground [GA]

http://arxiv.org/abs/1707.06276


Recent Planck observations of dust-polarization in the Galaxy have revealed that the power in $E$ mode is twice than that in $B$ mode. Caldwell et. al. have formulated a theoretical model in the context of magnetohydrodynamic (MHD) turbulence and found it problematic to account for this result. In particular, they concluded that there is a very narrow range of theoretical parameters that could account for the observation. This poses a problem of whether the accepted description of MHD turbulence can apply to the interstellar medium. We revisit the problem and demonstrate that MHD turbulence corresponding to the high galactic latitudes range of Alfv\’en Mach numbers, i.e. $M_A\lesssim 0.5$, can successfully explain the available results for the $E$ to $B$ mode ratio.

Read this paper on arXiv…

D. Kandel, A. Lazarian and D. Pogosyan
Fri, 21 Jul 17
47/59

Comments: Submitted to MNRAS Letters. 5 pages, 3 figures