ИСТИНА

Most of GMCs in M33 are connected with spiral-like gaseous arms with the exception of the inner 2 kpc region where the link between them disappears (see Tosaki et al., 2011). We check whether it may be caused by the dynamic friction which retards the clouds. Using the simple semi-analytical dynamical model for this galaxy, we calculate the motion of non-evolved GMCs of different masses situated at different initial galactocentric distances in the disk plane. We demonstrate that the dynamical friction may really influence the orbits of GMCs in the central 2 kpc-size region if the typical lifetimes of GMCs are close to or greater than 108 yr, which is larger than the usually accepted values.