Related papers: M31's Undisturbed Thin Disk of Globular Clusters

The center of our disk galaxy, the Milky Way, is dominated by a boxy/peanut-shaped bulge. Numerous studies of the bulge based on stellar photometry have concluded that the bulge stars are exclusively old. The perceived lack of young stars…

The number of known globular clusters in the Galactic bulge has been increasing steadily thanks to different new surveys. The aim of this study is to provide a census of the newly revealed globular clusters in the Galactic bulge, and…

Star formation in starbursts appears to be biased toward compact clusters, with up to 20% of all stars formed in them. Observations with HST show that many of these clusters have luminosities (-9 > Mv > -16), UBVI colors, and half-light…

We analyse a set of very metal-poor stars for which accurate chemical abundances have been obtained as part of the ESO Large Program "First stars" in the light of the Gaia DR2 data. The kinematics and orbital properties of the stars in the…

(Note: this is a shortened version of the original "structured" A&A format abstract.) We performed a large optical spectroscopic and photometric survey of the Lynds~1630N and 1641 clouds. We provide a catalog of 132 confirmed young stars in…

We report on a study of young star cluster complexes in the spiral galaxy M51. Recent studies have confirmed that star clusters do not form in isolation, but instead tend to form in larger groupings or complexes. We use {\it HST} broad and…

Spiral galaxies must acquire gas to maintain their observed level of star formation beyond the next few billion years (Leroy et al. 2008). A source of this material may be the gas that resides between galaxies, but our understanding of the…

Globular clusters (GCs) provide statistically significant coeval populations of stars spanning various evolutionary stages, allowing robust constraints on stellar evolution model parameters and ages. We analyze eight old Milky Way GCs with…

The archaeological record of stars in the Milky Way opens a uniquely detailed window into the early formation and assembly of galaxies. Here we use 11,000 main-sequence turn-off stars with well-measured ages, [Fe/H], [$\alpha$/Fe], and…

The Milky Way is a unique laboratory, where stellar properties can be measured and analyzed in detail. In particular, stars in the older populations encode information on the mechanisms that led to the formation of our Galaxy. In this…

The emergence of the disc in our Galaxy and the relation of the thick and thin disc formation and evolution is still a matter of debate. The chemo-dynamical characterization of disc stars is key to resolve this question, in particular at…

We have identified a few thousand star clusters in the nearby, late-type spiral galaxy M101, including approximately 90 candidate ancient globular clusters (GCs), from multi-band Hubble Space Telescope (HST) images. We obtained follow-up…

The study of outer halo globular cluster (GC) populations can give insight into galaxy merging, globular cluster accretion and the origin of GCs. We use archival Subaru Hyper Suprime-Cam (HSC) data in concert with space-based GALEX, IRAC…

(ABRIDGED) Globular clusters trace the formation and evolution of the Milky Way and surrounding galaxies, and outline their chemical enrichment history. To accomplish these tasks it is important to have large samples of clusters with…

The role of metallicity in shaping protoplanetary disk evolution remains poorly comprehended. This study analyzes the disk fraction of 10 young (0.9-2.1 Myr) and low-metallicity (0.34-0.83 Z$_{\odot}$) clusters located in the outer Milky…

Recent observational studies have uncovered a small number of very metal-poor stars with cold kinematics in the Galactic disc and bulge. However, their origins remain enigmatic. We select a total of 138 Milky Way (MW) analogs from the TNG50…

The Andromeda galaxy (M 31) has experienced a tumultuous merger history as evidenced by the many substructures present in its inner halo. We use planetary nebulae (PNe) as chemodynamic tracers to shed light on the recent merger history of M…

This paper reports on a survey of star clusters in M31 based on archival images from the Hubble Space Telescope. Paper I (Krienke and Hodge 2007) reported results from images obtained with the Wide Field/Planetary Camera 2 (WFPC2) and this…

The triple nucleus of M31 consists of a population of old red stars in an eccentric disk (P1 and P2) and another population of younger A stars in a circular disk (P3) around M31's central supermassive black hole (SMBH). We argue that P1 and…

The stellar kinematics of galactic disks are key to constraining disk formation and evolution processes. In this paper, for the first time, we measure the stellar age-velocity dispersion correlation in the inner 20 kpc (3.5 disk scale…