SIMBAD references

2021MNRAS.500.2937A - Mon. Not. R. Astron. Soc., 500, 2937-2957 (2021/January-3)

The orbital evolution of UFDs and GCs in an evolving Galactic potential.

ARMSTRONG B.M., BEKKI K. and LUDLOW A.D.

Abstract (from CDS):

We use the second Gaia data release to investigate the kinematics of 17 ultra-faint dwarf galaxies (UFDs) and 154 globular clusters (GCs) in the Milky Way, focusing on the differences between static and evolving models of the Galactic potential. An evolving potential modifies a satellite's orbit relative to its static equivalent, though the difference is small compared to existing uncertainties on orbital parameters. We find that the UFD Bootes II is likely on its first passage around the Milky Way. Depending on the assumed mass of the Milky Way, the UFDs Triangulum II, Hydrus I, Coma Berenices, Draco II, and Ursa Major II, as well as the GC Pyxis, may also be on first infall so may be useful for constraining the mass of the Galaxy. We identify a clear kinematic distinction between metal-rich ([Fe/H] > -1.1) and metal-poor GCs ([Fe/H] <= -1.1). Although most metal-rich clusters occupy predominately prograde orbits, with low eccentricities (e ≃ 0.35) and similar specific angular momenta and orbital planes as the Galactic disc, seven show potentially retrograde orbits, the origin of which is unclear. Metal-poor clusters have more diverse orbits, higher eccentricities (e ≃ 0.65), and half of them have orbital planes offset from the disc by 60° to 120°-twice as many as the metal-poor GCs. The UFDs have similar θ and ph to the metal-poor GCs, suggesting a similar origin. We provide a catalogue of orbital parameters for UFDs and GCs for two different Galaxy masses and their observational uncertainties.

Abstract Copyright: © 2020 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society

Journal keyword(s): Galaxy: evolution - Galaxy: kinematics and dynamics - galaxies: dwarf - Local Group - galaxies: star clusters: general

Status at CDS : Large table(s) will be appraised for possible ingestion in VizieR.

Simbad objects: 178

goto Full paper

goto View the reference in ADS

To bookmark this query, right click on this link: simbad:2021MNRAS.500.2937A and select 'bookmark this link' or equivalent in the popup menu


2021.04.10-16:59:52

© Université de Strasbourg/CNRS

    • Contact