The NewHorizon simulation – to bar or not to bar

ABSTRACT We use the NewHorizon simulation to study the redshift evolution of bar properties and fractions within galaxies in the stellar masses range M⋆ = 107.25–1011.4$\, \rm {M}_\odot$ over the redshift range of z = 0.25–1.3. We select disc galaxies using stellar kinematics as a proxy for galaxy morphology. We employ two different automated bar detection methods, coupled with visual inspection, resulting in observable bar fractions of fbar = 0.070$_{{-0.012}}^{{+0.018}}$ at z ∼ 1.3, decreasing to fbar = 0.011$_{{-0.003}}^{{+0.014}}$ at z ∼ 0.25. Only one galaxy is visually confirmed as strongly barred in our sample. This bar is hosted by the most massive disc and only survives from z = 1.3 down to z = 0.7. Such a low bar fraction, in particular amongst Milky Way-like progenitors, highlights a missing bars problem, shared by literally all cosmological simulations with spatial resolution