Fig. 10 is an example of this geometry. Like SO galaxies (galaxies with little or no evidence of star-forming activity in the disk) E galaxies are found most frequently in regimes characterized by high galaxy density, i.e., areas most susceptible to interactions.
A. Irregular Galaxies and "Dust Lane" E Galaxies The elliptical sump formed midway between two extended plasma components is the result of the coming together of the magnetic field lines of two (or more) adjacent filaments. At early times, the topology of these field lines is that of two "clashing cymbals" (cf. [1, figs. 6 and 8], that is also the shape taken on by intergalactic plasma between the extended current-conducting components. Examples include not only irregularly shaped galaxies (Fig. 11) but also E and some SO galaxies with "dust lanes" [12]. The dust lanes are usually aligned perpendicular to the major axis between extended components (Fig. 12), as they must be for plasma pushed in from either filament.
B. Flattened E and SO Galaxies
Elliptical galaxies are classified in a sequence from EO to E7, according to the degree of apparent flattening. EO systems appear circular, and E7 are the most oblong known. All flatter galaxies seem to be spirals and, even among the E7's, many may be type SO, systems that resemble spirals but lack distinctive arms. In fact, E7 galaxies often show slight spiral arms or perturbances. The morphologies described above are the shape that Birkeland currents take when they are closely spaced [.....]
