Related papers: Multiple spiral patterns in the transitional disk …

HR4796 is a young, early A-type star harbouring a well structured debris disk, shaped as a ring with sharp inner edges. It forms with the M-type star HR4796B a binary system, with a proj. sep. ~560 AU. Our aim is to explore the surroundings…

We present $H$- and $K_{\rm s}$-bands observations of the LkH$\alpha$ 330 disk with a multi-band detection of the large gap and spiral-like structures. The morphology of the outer disk ($r\sim$$0\farcs3$) at PA=0--45$^\circ$ and…

(Pre-)transitional disks show gaps and cavities that can be related with on-going planet formation. According to theory, young embedded planets can accrete material from the circumplanetary and circumstellar disks, so that they could be…

We refine the gap size measurements of the disk surrounding the Herbig Ae star HD 100546 in the N band. Our new mid-infrared interferometric (MIDI) data have been taken with the UT baselines and span the full range of orientations. The…

We present a detailed study of the massive star-forming region G35.2-0.74N with ALMA 1.3 mm multi-configuration observations. At 0.2" (440 au) resolution, the continuum emission reveals several dense cores along a filamentary structure,…

In this paper we discuss the influence of gravitational instabilities in massive protostellar discs on the dynamics of dust grains. Starting from a Smoothed Particle Hydrodynamics (SPH) simulation, we have computed the evolution of the dust…

Simulations of massive star formation predict the formation of discs with significant substructure, such as spiral arms and clumps due to fragmentation. Here we present a semi-analytic framework for producing synthetic observations of discs…

Scattered light imaging has revealed nearly a dozen circumstellar disks around young Herbig Ae/Be stars$-$enabling studies of structures in the upper disk layers as potential signs of on-going planet formation. We present the first images…

We present the first scattered-light images of two debris disks around the F8 star HD 104860 and the F0V star HD 192758, respectively $\sim45$ and $\sim67$ pc away. We detected these systems in the F110W and F160W filters through our…

HD 142527 is a well-studied intermediate-mass T Tauri star surrounded by a transitional disk with a large dust cavity, spiral structures, and an accreting low-mass companion. Despite extensive observations, the system's inner regions remain…

We have conducted a study of optical and HI properties of spiral galaxies (size, luminosity, H-alpha flux distribution, circular velocity, HI gas mass) to investigate causes (e.g., nature versus nurture) for variation within the cluster…

We recently reported the discovery of a regular corrugation pattern in the HI disk of the isolated, edge-on spiral galaxy IC2233. Here we present measurements of the vertical structure of this galaxy at several additional wavelengths,…

The protoplanetary disc HD 100453 exhibits a curious combination of spirals, shadows and a relative misalignment between the observed outer disc and inferred inner disc. This disc is accompanied by a secondary star on a bound orbit exterior…

Young accreting stars drive outflows that collimate into jets, which can be seen hundreds of au from their driving sources. Accretion and outflow activity cease with system age, and it is believed that magneto-centrifugally launched disk…

We present far-infrared spectroscopic observations, taken with the Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory, of the protoplanetary disk around the pre-main-sequence star HD 100546. These…

We investigate the nature of the innermost regions of seven circumstellar disks around pre-main-sequence stars. Our object sample contains disks apparently at various stages of their evolution. Both single stars and spatially resolved…

The rarity of young massive stars combined with the fact that they are often deeply embedded has limited the understanding of their formation. Ground based mid-infrared (IR) interferometry is one way of securing the spatial resolution…

Giant planets form in protoplanetary disks while these disks are still gas-rich, and can reveal their presence through the annular gaps they carve out. HD 100546 is a gas-rich disk with a wide gap between between a radius of ~1 and 13 AU,…

High-resolution, millimeter observations of disks at the protoplanetary stage reveal substructures such as gaps, rings, arcs, spirals, and cavities. While many protoplanetary disks host such substructures, only a few at the younger…

Hydrodynamical simulations show that a pair of spiral arms can form in the disk around a rapidly-growing young star and that the arms are crucial in transporting angular momentum as the disk accretes material from the surrounding envelope.…