Speaker
Description
Stellar bars are non-axisymmetric structures located in the inner regions of galaxies; they
play a crucial role in the dynamical evolution of their host galaxies. They are observed in approximately 30\% of disc galaxies in the local Universe. In this study, we analyze the impact of different environments on bar formation and evolution using the TNG100 and TNG50 simulations from the IllustrisTNG project. Our samples consist of 1719 satellite galaxies with stellar masses $M_{\star} \geq 10^{10} \, M_\odot$ for TNG100 and 859 satellite galaxies with $M_{\star} \geq 10^{9} \, M_\odot$ for TNG50 at redshift $z = 0$. To characterize the environments, we classified the host halos by their total mass into three categories: massive ($M_h \geq 10^{14} \, M_\odot$), intermediate ($10^{13} < M_h < 10^{14} \, M_\odot$), and low-mass ($M_h \leq 10^{13} \, M_\odot$) halos. We find that both the bar fraction and bar lengths normalized by the effective radius slightly decrease with increasing clustercentric distance across all halo mass bins, while the bar lengths remain approximately constant. Moreover, at fixed clustercentric distance, the bar fraction increases with halo mass. This trend may be explained by the fact that the most massive galaxies—which are more likely to host bars—tend to reside in more massive halos. Additionally, we observe a strong correlation between bar presence and the stellar assembly history of galaxies. Galaxies that assembled earlier, especially those located within $0.5 \, R_{200}$ of the cluster center, show a higher bar fraction. This suggests that early assembly history could promote bar formation. Our results indicate a mild environmental dependence of bar presence, but a stronger link with stellar assembly history. These findings contribute to a better understanding of the physical mechanisms behind bar formation and their connection to galaxy evolution in diverse environments.
