相关论文: Tracing the Early Milky Way with Globular Clusters…
The majority of the inhomogeneities in the chemical composition of Globular Cluster (GC) stars appear due to primordial enrichment by hot-CNO cycled material processed in stars belonging to a first stellar generation. Either massive AGB…
The spatial distribution of known globular clusters (GCs) in the Milky Way shows that the current census of GCs is incomplete in the direction of the Galactic plane. We present the discovery of two new GCs located close to the Galactic…
The fraction of stellar mass contained in globular clusters (GCs), also measured by number as the specific frequency, is a fundamental quantity that reflects both a galaxy's early star formation and its entire merging history. We present…
Globular Clusters (GCs) provide valuable insight into the properties of their host galaxies' dark matter halos. Using N-body simulations incorporating semianalytic dynamical friction and GC-GC merger prescriptions, we study the evolution of…
Abundance observations indicate the presence of often surprisingly large amounts of neutron capture (i.e., s- and r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the…
Recent investigations of the double red clump in the color-magnitude diagram of the Milky Way bulge cast serious doubts on the structure and formation origin of the outer bulge. Unlike previous interpretation based on an X-shaped bulge,…
The Milky Way contains several distinct old stellar components that provide a fossil record of its formation. We can understand their spatial distribution and kinematics in a hierarchical formation scenario by associating the proto-galactic…
The long term goal of large-scale chemical tagging is to use stellar elemental abundances as a tracer of dispersed substructures of the Galactic disk. The identification of such lost stellar aggregates and the exploration of their chemical…
We present absorption line indices measured in the integrated spectra of globular clusters both from the Galaxy and from M 31. Our samples include 41 Galactic globular clusters, and more than 300 clusters in M 31. The conversion of…
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…
Chemical tagging has great promise as a technique to unveil our Galaxy's history. Grouping stars based on their similar chemistry can establish details of the star formation and merger history of the Milky Way. With precise measurements of…
Recent progress in studies of globular clusters has shown that they are not simple stellar populations, being rather made of multiple generations. Evidence stems both from photometry and spectroscopy. A new paradigm is then arising for the…
Globular clusters (GCs) are found in all types of galaxies and harbor some of the most extreme stellar systems, including black holes that may dynamically assemble into merging binaries (BBHs). Uncertain GC properties, including when they…
Although globular clusters are generally chemically homogeneous, substantial abundance variations are sometimes seen even among unevolved main sequence stars, especially for the CNO group of elements. Multi-object intermediate-dispersion…
We have investigated the properties of a group of $\gamma$-ray emitting globular clusters (GCs) which have recently been uncovered in our Galaxy. By correlating the observed $\gamma$-ray luminosities $L_{\gamma}$ with various cluster…
In the center of the Milky Way, as well as in many other galaxies, a compact star cluster around a very massive black hole is observed. One of the possible explanations for the formation of such Nuclear Star Clusters is based on the…
Context: Globular clusters (GCs) in the outer halo are important probes of the composition and origin of the Galactic stellar halo. Aims: We derive chemical element abundance ratios in red giants belonging to the remote (R~90 kpc) GC Pal 3…
NGC 2419 is one of the remotest star clusters in the Milky Way halo and its exact nature is yet unclear: While it has traits reminiscent of a globular cluster (GC), its large radius and suggestions of an abundance spread have fueled the…
Observations of pulsars in globular clusters (GCs) give evidence that more >10-20% of neutron stars (NSs) ever formed in GCs were retained there. However, the velocity distribution of field pulsars peaks at 5-10 times the escape velocities…
In this short communication we consider the possibility that stars less evolved than the polluters are the source of the dilution needed to explain the observed composition of second-generation globular cluster (GC) stars and the Na-O and…