Related papers: Can Star-Disk Collisions Explain the Missing Red G…
We study the evolution of giant clumps in high-z disc galaxies using AMR cosmological simulations at redshifts z=6-1. Our sample consists of 34 galaxies, of halo masses 10^{11}-10^{12}M_s at z=2, run with and without radiation pressure (RP)…
The ``Little Red Dots'' (LRDs) are red and compact galaxies detected in JWST deep fields, mainly in the redshift range $z=4-8$. Given their compactness and the inferred stellar masses in the hypothesis that LRDs are starburst galaxies, the…
Structure of a quasi-stationary stellar cluster is modelled assuming that it is embedded in the gravitational field of a super-massive black hole. Gradual orbital decay of stellar trajectories is caused by the dissipative interaction with…
The detection with CoRoT of solar-like oscillations in nearly 800 red giants in the first 150-days long observational run paves the way for detailed studies of populations of galactic-disk red giants. We investigate which information on the…
Star-forming disk galaxies at high redshift are often subject to violent disk instability, characterized by giant clumps whose fate is yet to be understood. The main question is whether the clumps disrupt within their dynamical timescale…
Recent observations indicate that the progenitors of globular clusters (GCs) at high redshifts had high average stellar surface densities above $10^5\, \mathrm{M}_\odot\, \mathrm{pc}^{-2}$. The internal structure and kinematics of the…
On the basis of the near infrared observations of bulge red clump stars near the Galactic center, we have determined the galactocentric distance to be R_0 = 7.52 +- 0.10 (stat) +- 0.35 (sys) kpc. We observed the red clump stars at |l| < 1.0…
The history of star formation in the strong gravitational potential of the Galactic center has been of much interest, recently. We propose that the sub-parsec-scale disk of massive stars orbiting the massive black hole at the Galactic…
The Galactic centre contains several young populations within its central parsec: a disk between $\sim$0.05 and 0.5 pc from the centre, and the isotropic S-star cluster extending an order of magnitude further inwards in radius. Recent…
Among stars in Galactic globular clusters the carbon abundance tends to decrease with increasing luminosity on the upper red giant branch, particularly within the lowest metallicity clusters. While such a phenomena is not predicted by…
Carbon-deficient giants (CDGs) are a rare and chemically peculiar class of stars whose origins remain under active investigation. We present an asteroseismic analysis of the entire known CDG population, selecting 129 stars observed by…
Mass loss on the red giant branch (RGB) influences stellar evolution, properties of stellar populations, and Galactic chemical enrichment, yet remains poorly constrained observationally. Current models provide limited insight into how…
Mergers in the local universe present a unique opportunity for studying the transformations of galaxies in detail. Presented here are recent results, based on multi-wavelength, high-resolution imaging and medium resolution spectroscopy,…
We investigate encounters between giant molecular clouds (GMCs) and star clusters. We propose a single expression for the energy gain of a cluster due to an encounter with a GMC, valid for all encounter distances and GMC properties. This…
Red supergiants (RSGs) are an evolved stage in the life of intermediate massive stars (<25Mo). For many years their location in the H-R diagram was at variance with the evolutionary models. Using the MARCS stellar atmosphere models, we have…
Globular Cluster (GC) Color-Magnitude Diagrams (CMDs) are reasonably well understood in terms of standard stellar-evolution. However, there are still some open issues, such as fully accounting for the Horizontal Branch (HB) morphology in…
We investigate which conditions of dust attenuation and stellar populations allow models of dusty, continuously star-forming, bulge-less disk galaxies at 0.8<z<3.2 to meet the different colour selection criteria of high-z ``red'' galaxies…
During the last $\sim$ 30 Myr the nuclear stellar disk in the Galactic center has been the most prolific star forming region of the Milky Way when averaged by volume. Remarkably, the combined mass of the only three clusters present today in…
We propose a scenario in which massive stars form in a self-gravitating gaseous disc around a supermassive black hole. We find that once the surface density of the disc exceeds a critical value, the disc fragments into dense clumps. The…
Our Galactic Center hosts over 10% of the known massive stars in the Galaxy. The majority of these stars are located in three particularly massive clusters that formed within the past 5 Myr. While these clusters are extraordinary, their…