Fully 3D MHD simulations of astrophysical phenomena represent a challenge in standard data visualization for scientific purposes, for the amount of processed data and the wealth of scientific information they contain. However, virtual reality (VR) hardware and software are now commonly used in different fields for public outreach and education with excellent feedback. To this end, YouTube and online multimedia digital stores have several high-impact VR titles in the Astrophysics and Space Science categories of their catalogs. The routine, scientific use of VR environments, however, is still in its infancy.

In the first half of 2019, we launched 3DMAP-VR (3-Dimensional Modeling of Astrophysical Phenomena in Virtual Reality), a tool for visualizing 3D MHD models of astrophysical simulations, using VR equipment. The workflow combines: 1) accurate 3D HD/MHD simulations performed for scientific purposes using the FLASH code or the PLUTO code in HPC facilities, 2) the Paraview software (developed by Kitware Inc and distributed under a permissive BSD license) to realize the scenes and quickly have a VR representation of the model. The tool is used to analyze the numerical results in an immersive fashion, integrating the traditional screen displays. The models account for all the relevant physical processes in astrophysical phenomena: gravity, magnetic-field-oriented thermal conduction, energy losses due to radiation, gas viscosity, deviations from proton-electron temperature equilibration, deviations from the ionization equilibrium, cosmic rays acceleration, etc. The 3D representations of the models are realized using a mixed technique consisting of multilayer isodensity surfaces with different opacities.

Involved people
  • Bocchino Fabrizio
  • fabrizio.bocchino AT inaf.it INAF/OAPa
  • Daricello Laura
  • laura.daricello AT inaf.it INAF/OAPa
  • Leonardi Laura
  • laura.leonardi AT inaf.it INAF/OAPa
  • Miceli Marco
  • marco.miceli AT unipa.it Universita' di Palermo, INAF/OAPa
  • Orlando Salvatore
  • salvatore.orlando AT inaf.it INAF/OAPa
  • Pillitteri Ignazio
  • ignazio.pillitteri AT inaf.it INAF/OAPa


    Sketchfab is one of the largest open access platforms for immersive and interactive 3D models. We immediately recognized its enormous potential for dissemination and communication activities. We expect excellent synergy between our 3DMAP-VR project and Sketchfab to promote a wide dissemination of results for both scientific and public outreach purposes. To this end, we started a Sketchfab collection, "Universe in hands", which gathers different models of astrophysical objects and phenomena developed by our team for scientific purposes and published in international scientific journals and magazines. A Science Spotlight published by Sketchfab on the activity of INAF/OAPA can be found at the following link.

    Universe in hands by Salvatore Orlando on Sketchfab

    As an example of a model from this collection, the following describes the structure of Cassiopeia A, the outcome of the catastrophic explosion (a supernova) of a massive star at the end of its life about 340 years ago. The model shows the highly inhomogeneous distribution of stellar debris after the explosion; the different colors mark different chemical elements. The study of the structure of supernova remnants is fundamental in astrophysics because the remnants encode crucial information about the physical processes associated with the supernova engine.


    Supernova Remnant Cassiopeia A by Salvatore Orlando on Sketchfab

    Another example is the following model which describes the aftermath of a nova, a thermonuclear explosion occurring on the surface of a white dwarf star that is accumulating material from a companion red supergiant. The model shows the blast wave that expands through the inhomogeneous circumstellar medium 17 days after the explosion and the distribution of the ejected material, expanding with supersonic velocity after the explosion. These studies are important because the material ejected after the explosion gives us the unique opportunity to investigate the chemical composition of the outermost layers of the white dwarf, and the interaction of the blast wave with the surrounding medium allows us to explore the structure and density distribution of the circumstellar medium. All these pieces of information concur to unveil the latest stages of stellar evolution.

    The animation below shows the evolution of the magnetic field lines around a hot Jupiter while orbiting around its parent star. The simulation is based on a MHD model describing the so-called star-planet interaction (SPI) and applied to the case of HD 189733. The result is that the lines of the magnetic field around the planet are stretched along the direction of the orbital motion of the planet. This is a consequence of the gas evaporating from the planet itself due to the intense irradiation from the star. These simulations are important for the evolution of close-in planets around solar analogues.

    The example below shows a low-mass infant star during the phase of accretion of mass. The protostar (at the center of the scene) is analogous to our star, the Sun, when it was formed about 5 billion years ago. The protostar is surrounded by a circumstellar disk from which the star accretes matter. An intense activity due to sudden releases of energy (flares) near the disk gradually forms an extended hot corona (temperature of several million degrees) above the disk that emits in the X-ray band. The flares perturb the disk and trigger the accretion of mass onto the protostar. These studies are important to investigate how star systems similar to our solar system form and, therefore, to unravel the physical conditions that could lead to the formation of habitable planets and, ultimately, of life.