APOGEE physical properties of globular cluster tidal tails

TL;DR

This study uses APOGEE DR17 data to analyze the physical properties of globular cluster tidal tails, revealing correlations and implications for their formation scenarios and dark matter halo associations.

Contribution

First-time measurement of four tidal tail properties for 17 globular clusters, demonstrating correlations and linking properties to galaxy accretion groups.

Findings

$\sigma_{V_{LOS}}$ and $\sigma_{V_{Tan}}$ are highly correlated.

Tidal tails show a range of kinematic temperatures across accretion groups.

Results support diverse dark matter halo environments for globular cluster formation.

Abstract

A recent model prediction claimed that exists a correlation between the formation scenarios of globular clusters, i.e., whether they formed in situ, or in dark matter halos that were accreted into the Milky way, with some properties of their tidal tails, particularly, their widths ($w$), their dispersion in the z-component of the angular momentum ($\sigma$$_{\rm L_z}$ ), and in the line-of-sight ($\sigma$$_{\rm V_{LOS}}$) and tangential ($\sigma$$_{\rm V_{Tan}}$) velocities. I exploited the APOGEE DR17 data base and selected highly confident tidal tails members of 17 Milky Way globular clusters, for which the above four properties were computed for the first time. From all possible paired property combinations, I found that $\sigma$$_{\rm V_{LOS}}$ and $\sigma$$_{\rm V_{Tan}}$ resulted to be highly correlated, nearly to the identity relationship. This observation-based correlation resulted to be in an overall very good agreement with that arising from the aforementioned predictions. Additionally, when the four analyzed properties are linked to the accretion groups of the Milky way to which the globular clusters are meant to be associated, I found kinematically cold and hot tidal tails pertaining to globular clusters distributed in all the considered accretion groups. This outcome could be an evidence that globular clusters form in galaxies within a wide variety of dark matter halos, with different masses and profiles.