The Effect of Dark Matter Halo Shape on Bar Buckling and Boxy/Peanut
  Bulges
  It is well established that bars evolve significantly after they form in
galaxy discs, often changing shape both in and out of the disc plane. In some
cases they may bend or buckle out of the disc plane resulting in the formation
of boxy/peanut/x-shape bulges. In this paper we show that the dark matter halo
shape affects bar formation and buckling. We have performed N-body simulations
of bar buckling in non-spherical dark matter halos and traced bar evolution for
8 Gyr. We find that bar formation is delayed in oblate halos, resulting in
delayed buckling whereas bars form earlier in prolate halos leading to earlier
buckling. However, the duration of first buckling remains almost comparable.
All the models show two buckling events but the most extreme prolate halo
exhibits three distinct buckling features. Bars in prolate halos also show
buckling signatures for the longest duration compared to spherical and oblate
halos. Since ongoing buckling events are rarely observed, our study suggests
that most barred galaxies may have more oblate or spherical halos rather than
prolate halos. Our measurement of BPX structures also shows that prolate halos
promote bar thickening and disc heating more than oblate and spherical halos.
