Related papers: Disks around massive young stellar objects: are th…
Many protostellar disks show central cavities, rings, or spiral arms likely caused by low-mass stellar or planetary companions, yet few such features are conclusively tied to bodies embedded in the disks. We note that even small features on…
Circumstellar discs are essential for high mass star formation, while multiplicity, in particular binarity, appears to be an inevitable outcome since the vast majority of massive stars (> 8 Msun) are found in binaries (up to 100%). We…
We present images of the young stellar object ASR 41 in the NGC 1333 star forming region at the wavelengths of H_alpha and [SII] and in the I, J, H, and K-bands. ASR 41 has the near-infrared morphology of an edge-on disk object, but appears…
The formation and evolution of young low mass stars are characterized by important processes of mass loss and accretion ocurring in the innermost regions of their placentary circumstellar disks. Because of the large obscuration of these…
Based on SDSS data, we have selected a sample of nine edge-on spiral galaxies with bulges whose major axes show a high inclination to the disk plane. Such objects are called polar-bulge galaxies. They are similar in their morphology to…
(Abridged) Disks are observed around pre-main sequence stars, but how and when they form is still heavily debated. While disks around young stellar objects have been identified through thermal dust emission, spatially and spectrally…
Diverse protoplanetary disk morphology can result from planet-disk interaction, suggesting planetary presence. To date, most scattered light imaging campaigns have probed polarized light, which is only a fraction of the total light and not…
Massive stars form whilst they are still embedded in dense envelopes. As a result, the roles of rotation, mass loss and accretion in massive star formation are not well understood. This study evaluates the source of the Q-band, lambda=19.5…
The recent high angular resolution observations have shown that the transition between a globally symmetrical giant and a source surrounded by a spatially complex environment occurs relatively early, as soon as the external layers of the…
We present the results from a survey, designed to investigate the accretion process of massive young stellar objects (MYSOs) through near infrared narrow band imaging using the H$_2$ $\nu$=1-0 S(1) transition filter. A sample of 353 Massive…
Context: the observation of young stars with circumstellar disks suggests that the disks are dissipated, starting from the inner region, by the radiation of the central star and eventually by the formation of rocky planetesimals, over a…
We present new sub-arcsecond-resolution near-infrared polarimetric imaging and millimetre interferometry data on the circumstellar disk system in the Bok globule CB26. The data imply the presence of a M > 0.01 M_sun edge-on disk of >400 AU…
We present optical and IR spectra of a set of low-mass stars and brown dwarfs in the Coronet cluster (aged ~1Myr), obtained with the multifiber spectrograph FLAMES/VLT and IRS/Spitzer. The optical spectra reveal spectral types between M1…
We have carried out a near-infrared imaging survey of luminous young stellar outflow candidates using the United Kingdom Infrared Telescope. Observations were obtained in the broad band K (2.2 mu) and through narrow band filters at the…
The formation of a binary system surrounded by disks is the most common outcome of stellar formation. Hence studying and understanding the formation and the evolution of binary systems and associated disks is a cornerstone of star formation…
Circumstellar disks play an important role in many stages of the evolution of stars. However, it is only possible to directly image circumstellar disks for a few of the nearest stars. For massive stars, the situation is even more difficult,…
The Young Stellar Object (YSO) W33A is one of the best known examples of a massive star still in the process of forming. Here we present Gemini North ALTAIR/NIFS laser-guide star adaptive-optics assisted K-band integral-field spectroscopy…
The envelopes and disks that surround protostars reflect the initial conditions of star and planet formation and govern the assembly of stellar masses. Characterizing these structures requires observations that span the near-infrared to…
Observations of debris disks have significantly improved over the past decades, both in terms of sensitivity and spatial resolution. At near-infrared wavelengths, new observing strategies and post-processing algorithms allow us to…
We report the results of a study of the intermediate and high mass stars in the young, rich star-forming complex IC 1805, based on a combination of optical, near-infrared, and mid-infrared photometry, and classification spectra. These data…