相关论文: X-rays and young clusters: Membership, IMFs and di…
The SFiNCs (Star Formation in Nearby Clouds) project is an X-ray/infrared study of the young stellar populations in 22 star forming regions with distances <=1 kpc designed to extend our earlier MYStIX survey of more distant clusters. Our…
We are conducting a survey of several regions of high-mass star formation to assess their content and structure. The observations include Spitzer observations, ground-based optical and near-IR imaging surveys, and optical and IR spectra of…
NGC 6231 is a young cluster (age ~2-7 Myr) dominating the Sco OB1 association (distance ~1.59 kpc) with ~100 O and B stars and a large pre-main-sequence stellar population. We combine a reanalysis of archival Chandra X-ray data with…
We examine the spatial distribution of star clusters in NGC 628 using the statistical tool INDICATE to quantify clustering tendencies. Our sample, based on HST and JWST observations, is the most complete to date, spanning ages from 1 Myr to…
We present CCD photometry and a proper motion study of the young open star cluster, NGC 581 (M 103). Fitting isochrones to the colour magnitude diagram, we found an age of 16 +/- 4 Myr and a distance of roughly 3 kpc for this cluster. The…
Supermassive stars (SMS) with masses $M \gtrsim 10^3-10^4 M_{\odot}$, formed by runaway collisions in young, massive, and dense star clusters have been invoked as a possible solution to the puzzles raised by the presence of multiple stellar…
The origin of the lowest mass free-floating objects -- brown dwarfs and planetary-mass objects -- is one of the major unsolved problems in star formation. Establishing a census of young substellar objects is a fundamental prerequisite for…
We have conducted a kinematic study of 165 young M dwarfs with ages of <300 Myr. Our sample is composed of stars and brown dwarfs with spectral types ranging from K7 to L0, detected by ROSAT and with photometric distances of <25 pc assuming…
Studies during the last decade have revealed that nearly all Globular Clusters (GCs) host multiple populations (MPs) of stars with a distinctive chemical patterns in light elements. No evidence of such MPs has been found so far in…
We study the stellar cluster population in M81, using the HST/ACS images in the filters F435W, F606W and F814W that cover a total field of view of approximately 140 square arcmin. We present details about the selection criteria, which were…
Young massive clusters are dense aggregates of young stars that form the fundamental building blocks of galaxies. Several examples exist in the Milky Way Galaxy and the Local Group, but they are particularly abundant in starburst and…
We look for very low-mass members in open clusters with different ages placed at different distances. The main goal is to produce a reliable census of low-mass stars for each of the clusters and derive the Initial Mass Function. To achieve…
We present $UBVI_c$ CCD photometry of the young open cluster Stock 8 with the aim to study the basic properties and star formation scenario in this region. The radius of the cluster is found to be $\sim 6^{\prime}$ ($\sim 3.6$ pc) and the…
As a young massive cluster in the Central Molecular Zone, the Arches cluster is a valuable probe of the stellar Initial Mass Function (IMF) in the extreme Galactic Center environment. We use multi-epoch Hubble Space Telescope observations…
Star cluster formation in the early universe and their contribution to reionization remains to date largely unconstrained. Here we present JWST/NIRCam imaging of the most highly magnified galaxy known at z ~ 6, the Sunrise arc. We identify…
Globular clusters are often assumed to be good tracers of major star formation episodes in their host galaxies. While observations over the past 2 decades have confirmed the presence of young objects with globular cluster-like properties in…
We present a statistical method to derive the mass functions of open clusters using sky survey data such as the 2 Micron All Sky Survey and the Guide Star Catalogue. We have used this method to derive the mass functions in the…
The mass of unresolved young star clusters derived from spectro-photometric data may well be off by a factor of 2 or more once the migration of massive stars driven by mass segregation is accounted for. We quantify this effect for a large…
We have conducted a study of star formation in the outer Galaxy from 65\degr$< l <$265\degr~in the region observed by the GLIMPSE360 program. This {\it Spitzer} warm mission program mapped the plane of the outer Milky Way with IRAC at 3.6…
X-ray observations of galaxy clusters potentially provide powerful cosmological probes if systematics due to our incomplete knowledge of the intracluster medium (ICM) physics are understood and controlled. In this paper, we present mock…