Origin of the Milky Way bulge velocity-dispersion peak and contribution of stellar knots

Determine the origin of the Milky Way bulge’s central line-of-sight velocity-dispersion peak and establish whether centrally concentrated stellar knots contribute to this kinematic feature.

Background

The paper identifies central stellar knots in CIELO simulated galaxies as deeply bound, compact stellar overdensities and compares their properties with observational studies of the Milky Way bulge. The Milky Way’s central velocity-dispersion peak has been associated with possible central mass concentration, orbital anisotropy, or other dynamical structures. The authors state that the origin of this feature and the possible role of stellar knots in producing it remain unresolved. They note that a forthcoming comparison with an updated Milky Way bulge kinematic map will project the simulated knots into observational space to address the issue.

References

The origin of the $\sigma$-peak~\citep{zoccali+2014, valenti+2018, quezada2025} and the potential contribution of structures such as stellar knots to this kinematic feature remain open questions.

— The properties of central stellar knots embedded in galactic bulges of CIELO simulations  (2609.11465 - Acosta-Tripailao et al., 10 Sep 2026) in Section 5, Conclusions (Section \ref{sec:conc})