2007ApJ...662..250F

We simulate the bulge formation in very late type dwarf galaxies from circumnuclear super star clusters (SSCs) moving in a responding cuspy dark matter halo (DMH). The simulations show that (1) the response of a DMH to the sinking of SSCs is detectable only in the region interior to about 200 pc. The mean logarithmic slope of the responding DM density profile over that area displays two different phases: a very early decrease followed by an increase until it approaches 1.2 at the age of 2 Gyr. (2) The detectable feedbacks of the DMH response on the bulge formation turned out to be very small, in the sense that the formed bulges and their nuclear cusps in the fixed and the responding DMH are basically the same; both are consistent with HST observations. (3) The yielded mass correlation of bulges to their nuclear (stellar) cusps and the time evolution of the cusps' mass are in accordance with recent findings for relevant relations. In combination with the consistency of effective radii of nuclear cusps with observed quantities of nuclear clusters, we believe that the bulge formation scenario that we proposed could be a very promising mechanism for forming nuclear clusters.