Can bars erode cuspy halos?

Abstract

One of the major and widely known small scale problem with the Lambda CDM model of cosmology is the “core-cusp” problem. In this study we investigate whether this problem can be resolved using bar instabilities. We see that all the initial bars are thin (b/a < 0.3) in our simulations and the bar becomes thick ( b /a > 0.3) faster in the high resolution simulations. By increasing the resolution, we mean a larger number of disk particles. The thicker bars in the high resolution simulations transfer less angular momentum to the halo. Hence, we find that in the high resolution simulations it takes around 7 Gyr for the bar to remove inner dark matter cusp which is too long to be meaningful in galaxy evolution timescales. Physically, the reason is that as the resolution increases, the bar buckles faster and becomes thicker much earlier on.