How does nature form stable, long-lived magnetic structures which display considerable polarization (about 60% at 10.55 GHz in the Snake)? In 1988 I had modeled others of the dozens of filaments seen uniquely at the galactic center in terms of an electrodynamic view, in which currents set up coherent magnetic pinches. Such self-organizing filaments can exist in laboratory plasmas for long times; the galactic ones could be at least a million years old, as estimated by the time that shear forces would disrupt them.
The electrodynamic view uses pinch forces of currents to form filaments, driven by the E = v x B of conducting molecular clouds moving across a strong milliGauss ambient, ordered field. A return current must then flow at larger radii, making a closed loop which has a springy flexability, able to withstand the turbulent velocity fields known near the galactic center. The picture then anticipates that aberrant molecular clouds, moving contrary to the general galactic rotation, should accompany each filament. This prediction has held up as more filaments were found.
While I had predicted kinks then as arising from a current- driven instability, the Snake provided a further clue: it has two kinks, but does not break up into a large-scale sausage instability.
In a new paper, I show that this constrains the pinch ratio (azimuthal B/ longitudinal B) to approximately 1, so that the overall circuit created by clouds must construct a azimuthal pinching field, comparable to the longitudinal "backbone" field of the global galactic center.
Given this, a detailed nonlinear analysis of large kink excursions shows that the movement should drive shocks. This in turn produces particle acceleration, which then explains the observed peaked synchrotron emission at the kink maxima.
Further, other current-driven instabilities can occur. Filamentary instabilities can rapidly evolve in the acceleration zones which set up the global magnetic structures. (Perhaps in the observed H II regions at the Snake's northern end.)
In this view, the Snake has kinks because it is the farthest from the galactic center, so the "backbone" field is weaker and the pinch field can overcome its restraint. A circuit picture seems capable of qualitative agreement with the Snake's properties. But it cannot yet explain why the magnetic energy densities near the center are by far the largest seen in the galaxy, comparable with the Keplerian kinetic energy density, and so highly ordered. Clearly some even larger phenomena, or "circuit", must be found.