3D models of the circumstellar environments of evolved stars: Formation of multiple spiral structures

Abstract

We present 3D hydrodynamic models of the interaction between the outflows of evolved, pulsating, Asymptotic Giant Branch (AGB) stars and nearby ($<3$ stellar radii) sub-stellar companions ($M_{\mathrm{comp}}\lesssim 40$ M${}_J$). Our models show that due to resonances between the orbital period of the companion and the pulsation period of the AGB star, multiple spiral structures can form; the shocks driven by the pulsations are enhanced periodically in different regions as they encounter the denser material created by the sub-stellar companion's wake. We discuss the properties of these spiral structures and the effect of the companion parameters on them. We also demonstrate that the gravitational potential of the nearby companion enhances the mass loss from the AGB star. For more massive ($M_{\mathrm{comp}}>40$ M${}_J$) and more distant companions ($>4$ stellar radii), a single spiral arm forms. We discuss the possibility of observing these structures with the new generations of high-resolution, high-sensitivity instruments, and using them to `find' sub-stellar companions around bright, evolved stars. Our results also highlight possible structures that could form in our solar system when the Sun turns into an AGB star.

31 pages, 30 figures, accepted for publication at MNRAS

References in corpus (38)

• The James Webb Space Telescope
• SPLASH: An interactive visualisation tool for Smoothed Particle Hydrodynamics simulations
• Low-Mass Binary Induced Outflows from Asymptotic Giant Branch Stars
• Hot Jupiters and Cool Stars
• Unexpectedly large mass loss during the thermal pulse cycle of the red giant R Sculptoris!
• Binarity in Carbon-Enhanced Metal-Poor stars
• A Giant Planet Candidate Transiting a White Dwarf
• Imaging the circumstellar envelopes of AGB stars
• Planet Engulfment by ~1.5-3 Solar-Mass Red Giants
• (Sub)stellar companions shape the winds of evolved stars
• A Planetary Mass Companion to the K0 Giant HD 17092
• ALMA data suggest the presence of a spiral structure in the inner wind of CW Leo
• The pulsation modes, masses and evolution of luminous red giants
• On the Dynamical Stability of the Solar System
• Luminosities and mass-loss rates of Local Group AGB stars and Red Supergiants
• A Substellar Companion to the Intermediate-Mass Giant 11 Com
• Exploring wind-driving dust species in cool luminous giants I. Basic criteria and dynamical models of M-type AGB stars
• The wonderful complexity of the Mira AB system
• Star-planet interactions: II. Is planet engulfment the origin of fast rotating red giants?
• Synthetic photometry for carbon-rich giants. IV. An extensive grid of dynamic atmosphere and wind models
• A Planet in a 0.6-AU Orbit Around the K0 Giant HD 102272
• Magnetic fields in planetary nebulae and post-AGB nebulae
• Slowly, slowly in the wind: 3D hydrodynamical simulations of wind mass transfer and angular-momentum loss in AGB binary systems
• A radial velocity survey for post-common-envelope Wolf-Rayet central stars of planetary nebulae: First results and discovery of the close binary nucleus of NGC 5189
• A Catalog of GALEX Ultraviolet Emission from Asymptotic Giant Branch Stars
• Binarity as the Origin of Long Secondary Periods in Red Giant Stars
• Three red giants with substellar-mass companions
• The extended molecular envelope of the asymptotic giant branch star ${\pi }^1$ Gruis as seen by ALMA I. Large-scale kinematic structure and CO excitation properties
• SPH modelling of companion-perturbed AGB outflows including a new morphology classification scheme
• Dynamic atmospheres and winds of cool luminous giants, II. Gradual Fe enrichment of wind-driving silicate grains
• SPH modelling of wind-companion interactions in eccentric AGB binary systems
• Semi-regular red giants as distance indicators I. The period-luminosity relations of semi-regular variables revisited
• The extended molecular envelope of the asymptotic giant branch star ${\pi }^1$ Gruis as seen by ALMA II. The spiral-outflow observed at high-angular resolution
• Precise radial velocities of giant stars. XI. Two brown dwarfs in 6:1 mean motion resonance around the K giant star $\nu$ Ophiuchi
• Rings and arcs around evolved stars. II. The Carbon Star AFGL 3068 and the Planetary Nebulae NGC 6543, NGC 7009 and NGC 7027
• A detailed view on the circumstellar environment of the M-type AGB star EP Aquarii I. High-resolution ALMA and SPHERE observations
• The future influence of six exoplanets on the envelope properties of their parent stars on the giant branches
• Two-wind interactions in binaries with two orbiting giant stars