APOGEE physical properties of globular cluster tidal tails

¹ Instituto Interdisciplinario de Ciencias Básicas (ICB), CONICET-UNCuyo, Padre J. Contreras 1300, M5502JMA, Mendoza, Argentina
² Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2290, C1425FQB, Buenos Aires, Argentina

^★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 5 November 2025
Accepted: 12 December 2025

Abstract

A recent model prediction claimed that there is 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) and some properties of their tidal tails, particularly their widths (w), and their dispersions in the z-component of the angular momentum (σ_LZ) and in the line-of-sight (σ_VLOS) and tangential (σ_VTan) velocities. I exploited the APOGEE DR17 database and selected highly confident tidal tail members of 17 Milky Way globular clusters, for which the above four properties were computed for the first time. From all the possible paired property combinations, I found that σ_VLos and σ_VTan resulted as highly correlated, nearly to the identity relationship. This observation-based correlation was in 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 with 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 evidence that globular clusters form in galaxies within a wide variety of dark matter halos, with different masses and profiles.