No abstract

High-angular resolution observations at submillimeter/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 arms or localized spur- or crescent-shaped features. The majority of theoretical studies with the aim of interpreting the observational results have focused on disk models with planets under the assumption that the disk substructures are due to disk–planet interaction. However, so far, only in very few cases have exoplanets been detected in these systems. Furthermore, some substructures are expected to appear before planets form, as they are necessary to drive the concentration of small solids which can lead to the formation of planetesimals. In this work we present observational predictions from high-resolution 3D radiative hydrodynamical models that follow the evolution of gas and solids in a prototoplanetary disk. We focus on substructures in the distribution of millimeter-sized and smaller solid particles produced by the vertical shear instability. We show that their characteristics are compatible with some of the shallow gaps detected in recent observations at sub-mm/mm wavelengths and present predictions for future observations with better sensitivity and angular resolution with ALMA and a Next Generation Very Large Array.

¿Cuándo Intranet se convierte en un éxito como herramienta de comunicación interna en las organizaciones? ¿Por qué algunas veces es un fracaso? En este artículo, las autoras discuten cómo la transmisión de información trasciende las posibilidades tecnológicas y la voluntad de los directores y depende, también, de las redes de comunicación informal.

We present simulations of the capabilities of the Next Generation Very Large Array to image at high angular resolution substructures in the dust emission of protoplanetary disks. The main goal of this study is to investigate the kinds of substructures that are expected by state-of-the-art 3D simulations of disks and that an instrument like the ngVLA, with its current design, can detect. The disk simulations adopted in this investigation consist of global 3D radiation-hydrodynamics models with embedded particles, the latter representing dust grains. Our work shows that the ngVLA can detect and spatially resolve, down to sub-astronomical unit scales in disks in nearby star forming regions, the dust continuum emission at 3mm from azimuthal asymmetric structures, as well as from weak rings and gaps produced in these models as a consequence of the vertical shear instability (VSI). This hydrodynamical instability has been proposed to generate turbulence in regions of weak coupling between the disk gas and magnetic field, as well as to form vortices which may be preferred locations of planetesimal formation.