Determine the baseline required to eliminate residual binary contamination

Determine whether a finite multi-epoch radial-velocity observing baseline can establish that no longer observation is required for recovering unbiased velocity dispersions in ultra-faint dwarf galaxies across different galaxy systems and instrument capabilities.

Background

The paper explains that unresolved binary orbital motion can inflate velocity-dispersion measurements in ultra-faint dwarf galaxies, particularly in dynamically cold systems. Although longer multi-epoch baselines identify more velocity-variable binaries, the necessary baseline depends on the binary period, eccentricity, mass ratio, measurement precision, and completeness of repeat observations.

The authors note that a finite observing baseline cannot guarantee removal of binaries whose time-averaged velocities remain offset from their center-of-mass velocities. Consequently, the existence of a definitive finite baseline after which additional monitoring is unnecessary remains unresolved and must be assessed in relation to each galaxy and observing setup.