Related papers: Probing the envelopes of massive young stellar obj…
Most, if not all, stars are now believed to produce energetic outflows during their formation. Yet, almost 20 years after the discovery of bipolar outflows from young stars, the origins of this violent phenomenon are not well understood.…
Circumstellar disks are an essential ingredient of the formation of low-mass stars. It is unclear, however, whether the accretion-disk paradigm can also account for the formation of stars more massive than about 10 solar masses, in which…
The young massive-star-forming region M17 contains optically visible massive pre-main-sequence stars that are surrounded by circumstellar disks. Such disks are expected to disappear when these stars reach the main sequence. The physical and…
High-quality K-band spectra of strongly reddened point sources, deeply embedded in (ultra-) compact HII regions, have revealed a population of 20 young massive stars showing no photospheric absorption lines, but sometimes strong Br-gamma…
Massive stars play a pivotal role in shaping their galactic surroundings due to their high luminosity and intense ionizing radiation. However, the precise mechanisms governing the formation of massive stars remain elusive. Complex organic…
We present medium-resolution (R~7000) near-infrared echelle spectroscopic data for 36 MYSOs drawn from the Red MSX Source (RMS) survey. This is the largest sample observed at this resolution at these wavelengths of MYSOs to date. The…
In contrast to most other galaxies, star-formation rates in the Milky Way can be estimated directly from Young Stellar Objects (YSOs). In the Central Molecular Zone (CMZ) the star-formation rate calculated from the number of YSOs with 24…
Time-domain studies of mid-infrared and submillimeter variability have shown that at least half of protostars are variable. We present a statistical analysis of mid-infrared variability among young stellar objects (YSOs) in the distant,…
A few years ago, we investigated MYSO G29.862-0.0044 (YSO-G29), an intriguing star-forming region at a distance of 6.2 kpc. Although the typical disc-jet scenario was proposed to explain the observations, it remained far from conclusive.…
We present Spitzer Space Telescope IRAC and MIPS observations toward a sample of nine high-mass star forming regions at a distance of around 2 kpc. Based on IRAC and MIPS 24 $\mu$m photometric results and 2MASS JHKs data, we carry out a…
We used Herschel Hi-GAL survey data to determine whether massive young stellar objects (MYSOs) are resolved at 70$\mu$m and to study their envelope density distribution. Our analysis of three relatively isolated sources in the l=30{\deg}…
Since the '80s the \textit{Einstein} observatory has shown the Young Stellar Objects (YSOs), emit X-rays with luminosities, in the 0.3--8 keV bandpass, up to $\rm 10^3$--$\rm 10^4$ times than the Sun and that the X-ray emission is highly…
Young stellar objects (YSOs) are the gold standard for tracing star formation in galaxies but have been unobservable beyond the Milky Way and Magellanic Clouds. But that all changed when the James Webb Space Telescope was launched, which we…
We perform a systematic study of evolutionary stages and stellar masses of young stellar objects (YSOs) in the Large Magellanic Cloud (LMC) to investigate properties of star formation of the galaxy. There are 4825 sources in our YSO sample,…
We aim to characterize the distribution and composition of circumstellar material around young massive stars, and to investigate exactly which physical structures in these objects are probed by long-baseline mid-infrared interferometric…
Resolving the environments of massive stars is crucial for understanding their formation mechanisms and their impact on galaxy evolution. An important open question is whether massive stars found in diffuse regions outside spiral arms…
The luminous Young Stellar Object (YSO) IRAS 07422-2001 is studied in the infrared. We discover star forming activity in embedded clusters located in a cloud detected at mid-IR wavelengths in emission. Multiple outflows are discovered from…
We have searched for massive molecular outflows in a sample of high-mass star forming regions, and we have characterised both the outflow properties and those of their associated molecular clumps. With a sample composed largely of more…
The optically invisible infrared-source NGC 2264 IRS 1 is thought to be a massive young stellar object (~10 Msun). Although strong infrared excess clearly shows that the central object is surrounded by large amounts of circumstellar…
High-mass star formation is not well understood chiefly because examples are deeply embedded, relatively distant, and crowded with sources of emission. Using VLA and VLBA observations of water and SiO maser emission, we have mapped in…