Geha Research Group

Paper I (Geha et al. 2026) presents a homogeneous spectroscopic dataset of 22,339 stars in 78 Milky Way dwarf galaxy satellites and globular clusters. All data were taken with the Keck II telescope and Deep Extragalactic Imaging Multiobject Spectrograph (DEIMOS) spectrograph using the 1200G grating. Catalogs include individual stellar radial velocities, equivalent width-based [Fe/H] metallicities, and membership estimates.

You can access the tables directly from ApJ or in alternative formats below. See Paper I Appendix for detailed description of each column:

• Table 1A [csv | fits] lists the Milky Way system names (e.g., Draco, NGC 4590), literature properties, and select measured system quantities (78 rows).
• Table 2A [csv | fits] lists observational details for each DEIMOS mask included in this work (411 rows). There are five additional rows in this table for overlapping masks in the Sgr and NGC6715 systems.
• Table 3A [csv | fits] is the primary data table, one row per unique star observed with DEIMOS. Measurements include velocity, CaT-based metallicity and membership estimates (22,339 rows).
• Table 4A [csv | fits] lists identified extragalactic sources with measured redshifts (2,097 rows).
• Table 5A [csv | fits] combines measurements for objects from both Tables 3A and 4A, and includes additional information (24,436 rows).

Paper II (Geha 2026) presents the largest self-consistent sample of spectroscopically-derived quantities for Milky Way satellite galaxies and globular clusters based on a homogeneous re-analysis of individual stars observed with the Keck/DEIMOS spectrograph. We determine uniform internal velocity dispersions, enclosed dynamical masses, mean [Fe/H] metalliticies, and internal metallicity spreads for systems with 10 or more member stars.

Access to integrated properties for Milky Way systems is available:

• Table 1 [csv | fits] provides velocity dispersions and metallicities for Milky Way satellite galaxies and globular clusters observed with Keck/DEIMOS.

This database is used in the following works:

• Willman 1 Revisited: The Kinematics, Chemistry, and Orbital Properties of a Potentially-Disrupting Dwarf Galaxy, Chiu, Geha, Cerny et al. (2026)
• No Observational Evidence for Dark Matter Nor a Large Metallicity Spread in the Extreme Milky Way Satellite Ursa Major III / UNIONS 1, Cerny et al. (2025)
• Discovery and Spectroscopic Confirmation of Aquarius III: A Low-mass Milky Way Satellite Galaxy, Cerny et al. (2025)