Related papers: Spiral Arm Pattern Motion in the SAO 206462 Protop…
Context. Planet formation is expected to take place in the first million years of a planetary system through various processes, which remain to be tested through observations. Aims. With the recent discovery, using ALMA, of two gaseous…
In this paper I describe numerical calculations of the motion of particles in a disk about a solar-mass object perturbed by a planet on a circular orbit with mass greater than 0.001 of the stellar mass. A simple algorithm for simulating…
While there have been nearly two dozen of spiral arms detected from planet-forming disks in near-infrared scattered light, none of their substellar drivers have been confirmed. By observing spiral systems in at least two epochs spanning…
Late-stage infall onto protoplanetary disks can produce large scale spiral arms. In this paper we used 3D smoothed particle hydrodynamics and radiative transfer simulations to study the kinematic perturbations induced in disks by infalling…
We analyze two-armed global spiral density wave modes generated by gravitational instability in razor-thin, non-viscous, self-gravitating protoplanetary disks to understand the dependence of spiral arm morphology (pitch angle $\alpha$ and…
We use a high resolution cosmological zoom simulation of a Milky Way-sized halo to study the observable features in velocity and metallicity space associated with the dynamical influence of spiral arms. For the first time, we demonstrate…
Different spiral generation mechanisms are expected to produce different morphological and kinematic features. In this first paper in a series we carefully study the parameters of spiral structure in 155 face-on spiral galaxies, selected…
The discovery of wide-orbit giant exoplanets has posed a challenge to our conventional understanding of planet formation by coagulation of dust grains and planetesimals, and subsequent accretion of protoplanetary disk gas. As an alternative…
During the evolution of protoplanetary disks into planetary systems we expect to detect signatures that trace mechanisms such as planet-disk interaction. Protoplanetary disks display a large variety of structures in recently published…
Context. Spiral arms in protoplanetary disks could be shown to be the manifestation of density waves launched by protoplanets and propagating in the gaseous component of the disk. At least two point sources have been identified in the L…
The origin and maintenance of spiral structure in galaxies, the correlation between different types of spiral structure and several proposed mechanisms for their generation, and the evolution of spiral arms of galaxies with time are…
Millimeter continuum spiral arms have so far only been detected in a handful of protoplanetary disks, and thus we have a limited understanding of the circumstances in which they can form. In particular, substructures in small disks…
To determine the origin of the spiral structure observed in the dust continuum emission of Elias 2-27 we analyze multi-wavelength continuum ALMA data with a resolution of $\sim$0.2 arcsec ($\sim$23au) at 0.89, 1.3 and 3.3mm. We also study…
We test the influence of spiral arms on the star formation activity of disk galaxies by constructing and fitting multi-wavelength SEDs for the two nearby spiral galaxies NGC 628 and NGC 4321, at a spatial scale of 1-1.5kpc scale. Recent…
The intriguing nearly face-on southern ringed spiral galaxy NGC 4622, the first galaxy definitively shown to have leading spiral structure, is revisited in this paper with new images from the Hubble Space Telescope's WFPC2, together with…
Gaseous substructures such as feathers and spurs dot the landscape of spiral arms in disc galaxies. One of the candidates to explain their formation is the wiggle instability of galactic spiral shocks. We study the wiggle instability using…
Making use of a set of detailed potential models for normal spiral galaxies, we analyze the disk stellar orbital dynamics as the structural and dynamical parameters of the spiral arms (mass, pattern speed and pitch angle) are gradually…
The generation of spiral arms and the mechanisms controlling their properties within a realistic cosmological framework - the complete understanding is still beyond our grasp. Using a statistically significant sample of Milky Way- and…
Companions at sub-arcsecond separation from young stars are difficult to image. However their presence can be inferred from the perturbations they create in the dust and gas of protoplanetary disks. Here we present a new interpretation of…
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…