Bar formation in submaximal disks: a challenge for Λ CDM by Tahere Kashfi et al. on Wednesday 30 November

Bar formation in cosmological simulations of galaxy formation remains

challenging. It was previously shown that the fraction of barred galaxies at

low stellar masses ($M_*<10^{10.5} M_\odot$) in TNG50 is too low compared to

observations. Here, we highlight another tension, also observed at higher

stellar masses, namely that barred galaxies in TNG50 appear to be maximal

disks, in the sense that the majority of the gravitational acceleration is

accounted for by baryons at the peak radius of the baryonic rotation curve,

while observations account for a substantial fraction of barred submaximal

disks. In this letter, we compare the barred fraction of submaximal disks in

the local Universe from the SPARC catalogue with that in the TNG50 simulation.

We show that, although SPARC tends to select against barred galaxies, the

fraction of barred submaximal disks in this dataset is significantly larger

than in TNG50. This result adds to the list of challenges related to predicting

the right statistics and properties of barred galaxies in $\Lambda$CDM

simulations of galaxy formation.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15599v1