Testing the Theory That Interstellar Filaments Are Formed by the Bennett Pinch With Recent Data

Using recent observational data, we here test the theory, first proposed by Carlqvist and Gahm, that astrophysical filaments are formed by the Bennett pinch process. In this process, current flowing along the axis of the filament creates a toroidal magnetic field, which in turn creates an inward electromagnetic pressure that draws plasma toward the axis of the filament. In such filaments, the inward pinching force and outwards kinetic forces are approximately equal–the Bennett pinch condition. We find that the Bennett pinch condition does in fact hold, as predicted by the theory, for a sample of interstellar filaments, including molecular clouds, such as Taurus, IC5146, the pipe nebula, the infrared dark cloud G035.39–00.33, as well as
$H\text{I}$
fibers at high galactic latitudes, supernova remnant SN1006. The currents are estimated to be about 10
¹²
–10
¹⁴
A. These values are similar to that estimated by Carlqvist and Gahm for Lynds204. The Bennett pinch relation is also applied to intergalactic filaments, such as the ridge between Abell 0399 and 0401. This filament is almost in equilibrium. These results reinforce the validity of the theory.