Related papers: Multi-layered characterization of hot stellar syst…
Globular clusters (GCs) are fundamental for understanding the integrated light of old stellar populations and galaxy assembly processes. However, the role of hot, evolved stars, such as horizontal branch (HB), extreme HB, and blue…
Aims: Develop a data-driven and statistically based method for finding such clumps in Integrals of Motion space for nearby halo stars and evaluating their significance robustly. Methods: We use data from Gaia EDR3 extended with radial…
We performed a systematic search for strong gravitational lenses using Hyper Suprime-Cam (HSC) data, focusing on galaxy-scale lenses combined with an environment analysis resulting in the identification of lensing clusters. To identify…
We present an innovative and widely applicable approach for the detection and classification of stellar clusters, developed for the PHANGS-HST Treasury Program, an $NUV$-to-$I$ band imaging campaign of 38 spiral galaxies. Our pipeline first…
Galactic dynamical structures are fossil records of the assembly histories of galaxies. By analyzing the cosmological hydrodynamical simulation TNG50, we find that a dynamical structure that we call the "hot inner stellar halo," defined by…
Aims. To search for these rare objects, we study 32 Galactic O-type stars that were reported as SB1s in the literature. In our sample we include Cyg X-1, which is known to host an accreting stellar-mass BH, and HD 74194, a supergiant fast…
Aims - We present the first results of a large spectroscopic survey of globular clusters and candidate globular clusters in the nearby M~31 galaxy. The survey is aimed at the classification of known candidate M~31 clusters and at the study…
In this work, we study the basic statistical properties of HI-selected galaxies extracted from six different semi-analytic models, all run on the same cosmological N-body simulation. One model includes an explicit treatment for the…
We collected radial velocities of more than 50.000 individual stars in 156 Galactic globular clusters (GGC) and matched them with HST photometry and Gaia DR2 proper motions. This allowed us to derive the GGC's mean proper motions and space…
Galaxy clusters are excellent probes to study the effect of environment on galaxy formation and evolution. Along with high-quality observational data, accurate cosmological simulations are required to improve our understanding of galaxy…
LS 5039 is one of a handful of X-ray binaries that have been recently detected at high-energy $\gamma$-rays, in this case, by the High-Energy Stereoscopy Array (H.E.S.S.). The nature of this system is unknown: both a black hole and a pulsar…
We present the first results of a new technique to detect, locate, and characterize young dissolving star clusters. Using HST/ACS archival images of the nearby galaxy IC2574, we performed stellar PSF photometry and selected the most massive…
We have used the Parkes Multibeam system and the Sloan Digital Sky Survey (SDSS) to assemble a sample of 195 galaxies selected originally from their HI signature to avoid biases against unevolved or low surface brightness objects. For each…
We used the HST WFPC2 to obtain I-band images of the centers of 81 brightest cluster galaxies (BCGs), drawn from a volume-limited sample of nearby BCGs. The images show a rich variety of morphological features, including multiple or double…
We present a homogeneous catalogue for blue straggler, red giant branch, horizontal branch and main-sequence turn-off stars in a sample of 35 clusters taken from the ACS Survey for Globular Clusters. As a result of the superior photometry…
Most Galactic Globular Clusters (GCs) harbour multiple populations of stars (MPs), composed of at least two generations: the first characterized by a "standard" $\alpha$-enhanced metal mixture, as observed in field halo stars of the Milky…
We identify 42 candidate groups lying between 1.8<z<3.0 from a sample of 3502 galaxies with spectroscopic redshifts in the zCOSMOS-deep redshift survey within the same redshift interval. These systems contain three to five spectroscopic…
The UV properties of old stellar populations have been subject of intense scrutiny from the late sixties, when the UV-upturn in early type galaxies was first discovered. Because of their proximity and relative simplicity, Galactic globular…
Depending on the stellar type, more than $\sim 50$\% and $\sim 15\%$ of stars in the field have at least one and two stellar companions, respectively. Hierarchical systems can be assembled dynamically in dense star clusters, as a result of…
We present new spectroscopic observations of 5 galaxies, members of the unusually active compact group HCG 16, observed using the Palomar 5m telescope. The high signal to noise ratios (S/N $\sim 70$) of the spectra allow us to study the…