Study of barred galaxies in IllustrisTNG100: the case of low surface brightness galaxies

ABSTRACT In this work, we compare the presence of stellar bars in low and high surface brightness galaxies (LSBs and HSBs, respectively) using the TNG100 simulation of the IllustrisTNG project. The sample consists of 4244 disc galaxies at $z=0$ with stellar mass M$\star \ge 10^{10}$ M$\odot$. We find a bar fraction of $24 \pm 1.73~{{\ \rm per\ cent}}$ in LSBs, similar to the $28 \pm 0.74~{{\ \rm per\ cent}}$ found in HSBs, consistent with observations. For a given stellar mass range, HSBs consistently exhibit a higher bar fraction compared to LSBs, except at M$\star > 10^{11}$ M$\odot$, where the difference vanishes. To explore the origin of this trend and its relation to host galaxy properties, we construct several control samples matched in stellar mass, spin, gas mass fraction, and bulge-to-total mass ratio. For galaxies with M$\star {<}10^{11}$ M$\odot$, the lower bar fraction in LSBs appears to be associated with their higher spin and gas content – factors known to inhibit bar formation and growth. At the high mass end, only the bulge-to-total mass ratio is capable of enhancing the bar fraction difference, although its effect is limited. We also study the role of the local environment through the tidal parameter. Our results suggest that, unlike in HSBs, where the bar fraction remains largely unaffected, tidal interactions may promote bar formation in LSBs, albeit with a smaller impact than the intrinsic physical properties. These findings provide insight into the physical conditions that shape the presence of bars in LSBs.