Origin of trailing-side enhanced velocity gradients in NGC 3627

Determine the physical mechanism responsible for the occurrence of enhanced velocity gradient regions on the trailing side of the bar in parts of NGC 3627, contrary to the leading-side association observed in other barred galaxies, and assess the role of boxy/peanut-shaped bulge orbital structures and spurs in producing this offset.

Background

In their object-specific notes, the authors report that enhanced velocity gradients along the bar in NGC 3627 are disconnected at ~1 kpc from the center, and notably some segments lie on the trailing rather than the leading side relative to CO peaks and the dust lane, unlike the other sample galaxies.

They suggest that orbital structures linked to the galaxy’s boxy/peanut-shaped bulge and spurs may affect gas inflow and relate to the observed offset, but explicitly state that the cause is unclear and requires investigation.

References

It is not clear why enhanced velocity gradient regions are located in the trailing side in some parts especially in this galaxy, as they are located along or at the leading side of the dust lane in other sample galaxies.

— Impacts of bar-driven shear and shocks on star formation (2405.00107 - Kim et al., 30 Apr 2024) in Appendix, Section “Notes on individual galaxies” — NGC 3627