Related papers: Multi-wavelength study of a young open cluster NGC…
Open clusters belonging to star-forming complexes are the leftovers from the initial stellar generations. The study of these young systems provides constraints to models of star formation and evolution as well as to the properties of the…
We present new near-infrared spectroscopic observations of the outer edges of the young stellar cluster around the supermassive black hole at the Galactic center. The observations show a break in the surface-density profile of young stars…
(abridged) We used the Chandra observatory to perform a deep (70 ksec) X-ray observation of the Gum 31 region and detected 679 X-ray point sources. This extends and complements the X-ray survey of the central Carina nebula regions performed…
Images and spectra of the open cluster NGC 3105 have been obtained with GMOS on Gemini South. The (i', g'-i') color-magnitude diagram (CMD) constructed from these data extends from the brightest cluster members to g'~23. This is 4 - 5 mag…
The spectroscopic and photometric signals of the star-to-star abundance variations found in globular clusters seem to be correlated with global parameters like the cluster's metallicity, mass and age. Understanding this behaviour could…
Integral field spectroscopy in the K-band (1.9-2.4um) was performed on four IR-bright star clusters and the two nuclei in NGC 4038/4039 (``The Antennae''). Two of the clusters are located in the overlap region of the two galaxies, and…
We use new WFC3 observations of the nearby grand design spiral galaxy M83 to develop two independent methods for estimating the ages of young star clusters. The first method uses the physical extent and morphology of Halpha emission to…
Different environmental conditions can play a crucial role in determining final products of the star formation process and in this context, less favorable activities of star formation are expected in the external regions of our Galaxy. We…
Aims: We investigated the X-ray emission from young stars and brown dwarfs in the sigma Orionis cluster (tau~3 Ma, d~385 pc) and its relation to mass, presence of circumstellar discs, and separation to the cluster centre by taking advantage…
NGC 2903 is a nearby barred spiral with an active starburst in the center and Hii regions distributed along its bar. We aim to analyse the star formation properties in the bar region of NGC 2903 and study the links with the typical bar…
This paper presents diffraction-limited 1-18 micron images of the young quadruple star system HD 98800 obtained with the W. M. Keck 10-m telescopes using speckle and adaptive optics imaging at near-IR wavelengths and direct imaging at…
Deep and wide-field optical photometric observations along with multiwavelength archival datasets have been employed to study the physical properties of the cluster NGC 6910. The study also examines the impact of massive stars to their…
Star clusters are ideal platforms for categorising X-ray emitting stars and to study X-ray emission as a function of stellar age and activity. We present a comprehensive study of an open star cluster, NGC2527, by combining data from…
A 90 ks Chandra HETG observation of the young stellar cluster NGC 6193 in the southern Ara OB1 association detected 43 X-ray sources in a 2' x 2' core region centered on the young O stars HD 150135 (O6.5V) and HD 150136 (O3+O6V). The…
We report the results of a recent study of young star clusters (YSCs) in luminous blue compact galaxies (BCGs). The age distributions of the YSCs suggest that the starburst episode in Haro 11, ESO 185-IG13, and Mrk 930 started not more than…
Wide field near-infrared observations and Spitzer Space Telescope IRAC observations of the DR21/W75 star formation regions are presented. The photometric data are used to analyse the extinction, stellar content and clustering in the entire…
The Orion Nebula Cluster and the molecular cloud in its vicinity have been observed with the ACIS-I detector on board the Chandra X-ray Observatory with 23 hours exposure. We detect 1075 X-ray sources: 91% are spatially associated with…
Optical photometric and spectroscopic data are presented that show an association of an ultraluminous X-ray source in NGC 7331 with a young star cluster of mass 1.1e5 solar masses and age 4.25 Myr. If the ULX is part of the bright stellar…
Mechanisms involved in the star formation process and in particular the duration of the different phases of the cloud contraction are not yet fully understood. Photometric data alone suggest that objects coexist in the young cluster NGC6530…
AIMS. While observational evidence shows that most of the decline in a star's X-ray activity occurs between the age of the Hyades (~8 x 10^8 yrs) and that of the Sun, very little is known about the evolution of stellar activity between…