The origin of pseudobulges in cosmological simulations of galaxy
  formation
  More than half of nearby disc galaxies have pseudobulges instead of classical
bulges that are though to be end-products of galaxy mergers. Pseudobulges are
presumed to develop overtime as a result of secular evolution of galaxy discs.
We report simulations of galaxy formation, in which two disc galaxies with
disky pseudobulges have formed. Based on the profile decomposition, the
bulge-to-total mass ratio of the simulated galaxies is 0.6 for one galaxy and
0.3 for the other. We find that the main formation mechanism of the
pseudobulges in our simulations is not the secular evolution of discs but
high-redshift starbursts. The progenitors of the pseudobulges form as
high-redshift discs with small scale lengths by rapid supply of low angular
momentum gas. By redshift 2, before the main disc formation, pseudobulge
formation has largely completed in terms of mass. The secular evolution such as
bar instability accounts for about 30 % of the bulge mass for one galaxy and
only 13 % for the other but does affect the final shape and kinematic
properties of the pseudobulges.
