We present precision radial velocities and stellar population parameters for 77 star clusters in the Local Group galaxy M33. Our GTC and WHT observations sample both young, massive clusters and known/candidate globular clusters, spanning ages ~ 10^6 - 10^10 yr, and metallicities, [M/H] ~-1.7 to solar. The cluster system exhibits an age-metallicity relation; the youngest clusters are the most metal-rich. When compared to HI data, clusters with [M/H] ~ -1.0 and younger than ~ 4 Gyr are clearly identified as a disc population. The clusters show evidence for strong time evolution in the disc radial metallicity gradient (d[M/H]dt / dR = 0.03 dex/kpc/Gyr). The oldest clusters have stronger, more negative gradients than the youngest clusters in M33. The clusters also show a clear age-velocity dispersion relation. The line of sight velocity dispersions of the clusters increases with age similar to Milky Way open clusters and stars. The general shape of the relation is reproduced by disc heating simulations, and the similarity between the relations in M33 and the Milky Way suggests that heating by substructure, and cooling of the ISM both play a role in shaping this relation. We identify 12 "classical" GCs, six of which are newly identified GC candidates. The GCs are more metal-rich than Milky Way halo clusters, and show weak rotation. The inner (R < 4.5 kpc) GCs exhibit a steep radial metallicity gradient (d[M/H]/dR = -0.29+-0.11 dex/kpc) and an exponential-like surface density profile. We argue that these inner GCs are thick disc rather than halo objects.
Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. II. Ages, metallicities, detailed elemental abundances, and connections to the Galactic thick disc
Insights into Galaxy Morphology and Star Formation: Unveiling Filamentary Structures around an Extreme Overdensity at $z \sim 1.5$ Traced by [OII] Emitters
The assembly of bulge-dominated galaxies: two evolutionary channels traced through morphology, kinematics, and environment with a hybrid classification pipeline
Universidade Cidade de São Paulo（圣保罗城市大学）；Universidade de São Paulo, IAG（圣保罗大学天体物理研究所）；California Institute of Technology（加州理工学院）；Instituto de Astrofísica de Canarias（加那利群岛天体物理研究所）；Universidad Técnica Federico Santa María（费德里科·Santa玛利亚技术大学）
Feedback in emerging extragalactic star clusters, FEAST: The relation between 3.3 $μ$m PAH emission and Star Formation Rate traced by ionized gas in NGC 628
The Radcliffe Wave as traced by young open clusters: Stellar parameters, activity indicators, and abundances of solar-type members of eight young clusters
The Cosmic Large-Scale Structure in X-rays (CLASSIX) Cluster Survey III: The Perseus-Pisces supercluster and the Southern Great Wall as traced by X-ray luminous galaxy clusters
