TY - JOUR
T1 - Alignment of the scalar gradient in evolving magnetic fields
AU - Sur, Sharanya
AU - Pan, Liubin
AU - Scannapieco, Evan
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/7/20
Y1 - 2014/7/20
N2 - We conduct simulations of turbulent mixing in the presence of a magnetic field, grown by the small-scale dynamo. We show that the scalar gradient field, ∇C, which must be large for diffusion to operate, is strongly biased perpendicular to the magnetic field, B. This is true both early on, when the magnetic field is negligible, and at late times, when the field is strong enough to back react on the flow. This occurs because ∇C increases within the plane of a compressive motion, but B increases perpendicular to it. At late times, the magnetic field resists compression, making it harder for scalar gradients to grow and likely slowing mixing.
AB - We conduct simulations of turbulent mixing in the presence of a magnetic field, grown by the small-scale dynamo. We show that the scalar gradient field, ∇C, which must be large for diffusion to operate, is strongly biased perpendicular to the magnetic field, B. This is true both early on, when the magnetic field is negligible, and at late times, when the field is strong enough to back react on the flow. This occurs because ∇C increases within the plane of a compressive motion, but B increases perpendicular to it. At late times, the magnetic field resists compression, making it harder for scalar gradients to grow and likely slowing mixing.
KW - ISM: abundances
KW - magnetic fields
KW - magnetohydrodynamics (MHD)
KW - turbulence
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U2 - 10.1088/2041-8205/790/1/L9
DO - 10.1088/2041-8205/790/1/L9
M3 - Article
AN - SCOPUS:84904151718
VL - 790
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
SN - 2041-8205
IS - 1
M1 - L9
ER -