Related papers: Multiple spiral arms in the disk around intermedia…
Spiral arms are observed in numerous protoplanetary discs. These spiral arms can be excited by companions, either on bound or unbound orbits. We simulate a scenario where an unbound perturber, i.e. a flyby, excites spiral arms during a…
Direct imaging observations of protoplanetary disks at near-infrared (NIR) wavelengths have revealed structures of potentially planetary origin. Investigations of observational signatures from planet-induced features have so far focused on…
Binary formation is an important aspect of star formation. One possible route for close-in binary formation is disk fragmentation$^{[1,2,3]}$. Recent observations show small scale asymmetries (<300 au) around young protostars$^{[2,4]}$,…
We present ALMA observations of the 2M1207 system, a young binary made of a brown dwarf with a planetary-mass companion at a projected separation of about 40 au. We detect emission from dust continuum at 0.89 mm and from the $J = 3 - 2$…
Young close binaries clear central cavities in their surrounding circumbinary disk from which the stars can still accrete material. This process takes place within the very first astronomical units, and is still not well constrained as the…
New high resolution, high sensitivity WSRT HI synthesis observations of the spiral galaxy NGC 3631 are presented. In the total atomic hydrogen map, the spiral arms are well distinguished from the interarm regions, while the sensitivity…
We present a new method of analysis for determining the surface geometry of five protoplanetary disks observed with near-infrared imaging polarimetry using Subaru-HiCIAO. Using as inputs the observed distribution of polarized intensity…
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…
The dynamics of planetesimals in the circumbinary debris disc of the quadruple star system HD 98800 are investigated. Evolving a spherical shell of test particles from a million years ago to the present day indicates that both coplanar and…
Transitional disks represent a short stage of the evolution of circumstellar material. Studies of dust grains in these objects can provide pivotal information on the mechanisms of planet formation. Dissimilarities in the spatial…
The circumstellar disk of AB Aurigae has garnered strong attention owing to the apparent existence of spirals at a relatively young stage and also the asymmetric disk traced in thermal dust emission. However, the physical conditions of the…
We present the result of an extensive search for non-axisymmetric structures in the dwarf satellite galaxy of M81: NGC 2976, using multiwavelength archival observations. The galaxy is known to present kinematic evidence for a bysimmetric…
The advent of high-resolution, near-infrared instruments such as VLT/SPHERE and Gemini/GPI has helped uncover a wealth of substructure in planet-forming disks, including large, prominent spiral arms in MWC 758, SAO 206462, and V1247 Ori…
High-angular resolution observations at sub-millimeter/millimeter wavelengths of disks surrounding young stars have shown that their morphology is made of azimuthally-symmetric or point-symmetric substructures, in some cases with spiral…
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…
The dynamical interactions between young binaries can perturb the material distribution of their circumstellar disks, and modify the planet formation process. In order to constrain the impact and nature of the binary interaction in the RW…
Some circumstellar disks are observed to show prominent spiral arms in infrared scattered light or (sub-)millimeter dust continuum. The spirals might be formed from self-gravity, shadows, or planet-disk interactions. Recently, it was…
We study star formation processes in the disc of the weakly barred grand design spiral galaxy M100 (NGC 4321) from a variety of images tracing recent massive star formation, old and young stars, dust, and neutral hydrogen. Differences…
We present high-resolution mid-infrared observations of the nearby late-type young binary system Hen 3-600. The binary, at a distance of $\sim$ 50 pc, could be a member of the TW Hydrae Association, the nearest known group of young stars,…
The Galactic center of the Milky-Way harbors a massive black hole (BH) orbited by a diverse population of young and old stars. A significant fraction of the youngest stars ($\sim4-7$ Myr) reside in a thin stellar disk with puzzling…