Probing Substellar Companions of Asymptotic Giant Branch Stars through Spirals and Arcs
Three dimensional hydrodynamical simulations show that the substellar mass objects produce detectable signatures, corresponding to density contrasts of 10--200 % and arm separations of 10--400 AU at 100 AU distance, for the wake induced by a Jupiter to brown dwarf mass object orbiting a solar mass AGB star.
Recent observations of strikingly well-defined spirals in the circumstellar envelopes of asymptotic giant branch (AGB) stars point to the existence of binary companions in these objects. In the case of planet or brown dwarf mass companions, an investigation of the observational properties of the spiral-onion shell wakes due to the gravitational interaction of these companions with the outflowing circumstellar matter has been carried out. Three dimensional hydrodynamical simulations show that the substellar mass objects produce detectable signatures, corresponding to density contrasts of 10--200 % and arm separations of 10--400 AU at 100 AU distance, for the wake induced by a Jupiter to brown dwarf mass object orbiting a solar mass AGB star. The results suggest that such features may probe unseen substellar mass objects embedded in the winds of AGB stars and may be useful in planning future high sensitivity/resolution observations with e.g., Atacama Large Millimeter/submillimeter Array.