FORMATION OF SLOW BARS IN EARLY-TYPE SPIRAL GALAXIES

It is shown that the conditions for the formation of a slow bar are si gnificantly relaxed if the disk rotates inside a massive, halo, as is often the case in galaxies, especially those of early types. This impl ies that the halo has a destabilizing effect on the instability of a s low bar-forming mode, while for the instability of a rapid bar, the ha lo is known to be one of the most effective stabilizing factors. At th e same time, the bending instability is saturated, with the system pre serving its initial disk-like shape if the halo is sufficiently massiv e.