On the stability of circumplanetary disks

p>Giant planets in the solar system have regular moons around them, observations suggest that their formation is linked with the host planet creation itself. Planets form from circumstellar disks material, this is product of the star forming process. Embedded giant protoplanets in circumstellar disks form a circumplanetary disk around them from the accreted circumstellar disk material, from this material moons should form. With the aim to study this phenomenon in detail, in this work,br /> hydrodynamic three dimensional simulations of planetary systems in formation are performed using the FARGO3D code. The evolution of a Jupiter-like protoplanet embedded in a protoplanetary disk orbiting a solar mass star is studied. We investigate the formation of the circumplanetary disk around the protoplanet. The circumplanetary disk is formed by vertical in ow of material which comes from the circumstellar disk. The circumplanetary disk follows a mass distribution given bynbsp;span class="math-tex">\(\Sigma_{\mathrm{CPD}} \propto r^{-1.9}\)/span> and span class="math-tex">\(\rho_{\mathrm{CPD}} \propto r^{-3}\)/span>. We found a thick disk with an aspect ratio of span class="math-tex">\(h/r \approx 0.4\)/span>. The disk rotates with a sub-keplerian profile, following a power law span class="math-tex">\(\Omega_{z} \propto r^{-1.7}\)/span>. It has a size given by 1/3 the Hill radius. The mass inside this radius is span class="math-tex">\(\sim 0.03\mathrm{m_p}\)/span>. Circumplanetary disks are gravitationally very stable structures. This stability is given by its dynamics, rather than its termodynamics. Hence, we expect that all circumplanetary disks are stable. This would imply that there is no moon formation due to gravitational instabilities. Nevertheless, circumplanetary disks have an ideal quantity of mass and angular momentum to form moons, they are excellent reservoirs to form moons around giant planets. Since they are a natural consequence of planetary formation, we expect that giantexoplanets have moon systems around them./p