1179 galaxies in the IllustrisTNG simulation

While cosmological simulations are powerful tools to study the formation and evolution of galaxies, they have often struggled to generate reasonable bar populations. We measure the fraction, size, and strength of bars in 3866 disk galaxies from the TNG100 run of the advanced cosmological simulation IllustrisTNG.

Consistent with observations, about 55% of disk galaxies with stellar mass M*~10^10.6^M{odot} are barred, and the relation between bar size and total stellar mass is similar to that found in near-infrared surveys. However, the formation of bars is suppressed in galaxies with M*<10^10.6^M{odot}, which may result from the difficulty TNG100 has in resolving short bars with radius <1.4kpc. In contrast, up to 75% of massive disk galaxies with M*>10^10.6^M{odot} have bars, ~10%-20% higher than observed.