NONLINEAR GALACTIC DYNAMOS AND THE MAGNETIC PITCH ANGLE
نویسندگان
چکیده
منابع مشابه
Nonlinear magnetic diffusion and magnetic helicity transport in galactic dynamos
We have extended our previous mean-field galactic dynamo model which included algebraic and dynamic alpha nonlinearities (Kleeorin et al. 2002), to include also a quenching of turbulent diffusivity. We readily obtain equilibrium states for the large-scale magnetic field in the local disc dynamo model, and these fields have strengths that are comparable to the equipartition field strength. We fi...
متن کاملThe role of magnetic helicity transport in nonlinear galactic dynamos
We consider the magnetic helicity balance for the galactic dynamo in the framework of the local dynamo problem, as well as in the no-z model (which includes explicitly the radial distribution of the magnetic fields). When calculating the magnetic helicity balance we take into account the redistribution of the small-scale and large-scale magnetic fields between the magnetic helicities, as well a...
متن کاملMagnetic helicity in galactic dynamos
Magnetic fields correlated on kiloparsec scales are seen in spiral galaxies. Their origin could be due to amplification of a small seed field by a turbulent galactic dynamo. We review the current status of the galactic dynamo, especially the constraints imposed by magnetic helicity conservation. We estimate the minimal strength of the large-scale magnetic field which could arise inspite of the ...
متن کاملGalactic dynamos driven by magnetic buoyancy
We consider a mean field dynamo model for the generation of galactic magnetic fields, in which the driving mechanism for the alpha-effect is the buoyancy-driven Parker instability, rather than the conventional cyclonic turbulence. The dominant quenching mechanism is a buoyant velocity, which lifts field away from the disc plane. Our modified alpha-effect is essentially nonlinear, as its magnitu...
متن کاملGalactic Dynamos and Galactic Winds
Spiral galaxies host dynamically important magnetic fields which can affect gas flows in the disks and halos. Total magnetic fields in spiral galaxies are strongest (up to 30 μG) in the spiral arms where they are mostly turbulent or tangled. Polarized synchrotron emission shows that the resolved regular fields are generally strongest in the interarm regions (up to 15 μG). Faraday rotation measu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2015
ISSN: 1538-4357
DOI: 10.1088/0004-637x/808/1/28