Related papers: The low-mass pre-main-sequence population of Sco O…
We present 237 new spectroscopically confirmed pre-main-sequence K and M-type stars in the young Upper Scorpius subgroup of the Sco-Cen association, the near- est region of recent massive star formation. Using the Wide-Field Spectrograph at…
Low-mass stars and sub-stellar objects are essential in tracing the initial mass function (IMF). We study the nearby young $\sigma$ Orionis cluster (d$\sim$408 pc; age$\sim$1.8 Myr) using deep NIR photometric data in J, W and H-bands from…
We present the first multiplicity-dedicated long baseline optical interferometric survey of the Scorpius-Centaurus-Lupus-Crux association. We used the Sydney University Stellar Interferometer to undertake a survey for new companions to 58…
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…
We present the first high spatial resolution X-ray study of the massive star forming region NGC 6357, obtained in a 38 ks Chandra/ACIS observation. Inside the brightest constituent of this large HII region complex is the massive open…
The ESO public survey VISTA Variables in the V\'ia L\'actea (VVV) has contributed with deep multi-epoch photometry of the Galactic bulge and the adjacent part of the disk over 526 square degrees. More than a hundred cluster candidates have…
We present here the first results from a high-resolution survey of the 12CO(J=1-0) emission across the northern part of the poorly-enriched Small Magellanic Cloud, made with the ATNF Mopra telescope. Three molecular complexes detected in…
We observe the 1.2 mm continuum emission around the OB cluster forming region G10.6-0.4, using the IRAM 30m telescope MAMBO-2 bolometer array and the Submillimeter array. Comparison of the Spitzer 24 $\mu$m and 8 $\mu$m images with our 1.2…
We present a VI photometric catalogue towards the open cluster Cr 121. XMM-Newton and ROSAT data are used to discover a low-mass pre-main sequence (PMS) along this sight-line. de Zeeuw et al (1999) identified Cr 121 as a moving group, using…
We have studied the kinematics of a unique sample of young open star clusters (OSCs) with high vertical velocities, $15<W<40$ km s$^{-1}$. The characteristics of these clusters were taken from the catalogue by Hunt and Reffert (2023), where…
We aim at identifying very low-mass isolated planetary-mass member candidates in the nearest OB association to the Sun, Upper Scorpius (145 pc; 5-10 Myr), to constrain the form and shape of the luminosity function and mass spectrum in this…
Young star clusters consisting of massive stars are the ideal sites to study the star formation processes and influence of massive stars on the subsequent star formation. NGC 1893 is a young star cluster associated with the HII region…
We report the discovery of low-mass PMS stars in the younger subgroup of the Cepheus OB3 association, Cep OB3b, using {\it UBVI} CCD photometry and spectroscopy. The location of a PMS is well defined in a V versus (V-I) colour-magnitude…
We present Spitzer, NIR and millimeter observations of the massive star forming regions W5-east, S235, S252, S254-S258 and NGC7538. Spitzer data is combined with near-IR observations to identify and classify the young population while 12CO…
For understanding the process of star formation it is essential to know how many stars are formed as singles or in multiple systems, as a function of environment and binary parameters. This requires a characterization of the primordial…
We present U, B, V, I broad-band, 6200A TiO medium-band and Halpha photometry of the Orion Nebula Cluster obtained with the WFI imager at the ESO/MPI 2.2 telescope. The nearly-simultaneous observations cover the entire ONC in a field of…
The distribution of young stars into OB associations has long been in need of updating. High-precision {\sl Gaia} early Data Release 3 astrometry, coupled with modern machine-learning methods, allows this to be done. We have compiled a…
We summarize observational results on the stellar population and star formation history of the Scorpius-Centaurus OB Association (Sco OB2), the nearest region of recent massive star formation. It consists of three subgroups, Upper Scorpius…
We describe our method to find the primordial binary population in the Sco OB2 association. We present the results of our ADONIS and VLT/NACO near-infrared adaptive optics binarity surveys of A and late-B stars in Sco OB2. We combine these…
The connection between high-mass stars and young stellar clusters has been well established by near-IR observations showing young massive stars in HII regions surrounded by clusters of lower mass stars. Mm-wave observations show that these…