Related papers: Open clusters in AurOB2
High-mass stars form in much richer environments than those associated with isolated low-mass stars, and once they reach a certain mass, produce ionised (HII) regions. The formation of these pockets of ionised gas are unique to the…
NGC 2264 is a young Galactic cluster and the dominant component of the Mon OB1 association lying approximately 760 pc distant within the local spiral arm. The cluster is hierarchically structured, with subclusters of suspected members…
We report NIR broad and narrow band photometric observations in the direction of the IRAS17149-3916 source that reveal the presence of a young cluster of massive stars embedded in an HII region coincident with RCW121. These observations,…
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…
We study the three dimensional arrangement of young stars in the solar neighbourhood using the second release of the Gaia mission (Gaia DR2) and we provide a new, original view of the spatial configuration of the star forming regions within…
We present a picture of star formation around the HII region Sh2-235 (S235) based upon data on the spatial distribution of young stellar clusters and the distribution and kinematics of molecular gas around S235. We observed 13CO(1-0) and…
This work aims at investigating the molecular gas component in the vicinity of two young stellar object (YSO) candidates identified at the border of the HII region G034.8-0.7 that is evolving within a molecular cloud shocked by the SNR W44.…
We report on the detection of optically thick free-free radio sources in the galaxies M33, NGC 253, and NGC 6946 using data in the literature. We interpret these sources as being young, embedded star birth regions, which are likely to be…
We present the results of a near-infrared adaptive optics survey with the aim to detect close companions to Hipparcos members in the three subgroups of the nearby OB association Sco OB2: Upper Scorpius (US), Upper Centaurus Lupus (UCL) and…
We present new high spectral resolution VLT/UVES spectroscopy and archival HST/STIS imaging and spectroscopy of the giant HII region Tol89 in NGC5398. From optical and UV HST images, we find that the star-forming complex as a whole contains…
Gas density and temperature in star forming regions around Sh2-235 are derived from ammonia line observations. This information is used to evaluate formation scenarios and to determine evolutionary stages of the young embedded clusters S235…
The intermediate- to high-mass star-forming region IRAS 20343+4129 is an excellent laboratory to study the influence of high- and intermediate-mass young stellar objects on nearby starless dense cores, and investigate for possible…
We report the discovery of nearly a dozen collimated outflows from young stellar objects embedded in the molecular filament that extends north of the Orion Nebula towards the H II region NGC 1977. The large number of nearly co-eval outflows…
We present an analysis of the structure and properties of the compact HII region Sh 2-89, and certain of the young stellar objects (YSOs) within this regime, using mid-infrared (MIR) mapping derived from the Spitzer Space Telescope (SST)…
We present a drift scan survey covering a ~5 deg by 50 deg region toward the southern portion of the Taurus-Auriga molecular cloud. Data taken in the B,R,I filters with the Quest-2 camera on the Palomar 48-inch telescope were combined with…
We present Spitzer-IRAC, NOAO 2.1meter-Flamingos, Keck-NIRC, and FCRAO-SEQUOIA observations of the massive star forming complex S254-S258, covering an area of 25x20 arc-minutes. Using a combination of the IRAC and NIR data, we identify and…
We present a study of active stellar forming regions in the environs of the HII region Sh2-205. The analysis is based on data obtained from point source catalogues and images extracted from 2MASS, MSX, and IRAS surveys. Complementary data…
We have discovered a number of very small isolated HII regions 20-30 kpc from their nearest galaxy. The HII regions appear as tiny emission line dots (ELdots) in narrow band images obtained by the NOAO Survey for Ionization in Neutral Gas…
We made a multi-wavelength study of young massive star clusters (YSCs) in the interacting galaxy ARP 24, using the optical and ultraviolet images from Hubble Space Telescope (HST), Sloan Digital Sky Survey, and Galaxy Evolution Explorer;…
The apparent lack of massive O-type stars near the zero-age main sequence (at ages < 2 Myr) is a topic widely discussed. Different explanations for this elusive detection have been proposed, but no firm conclusions have been reached yet. We…