Speaker
Description
The heavy mass-loss experienced by evolved asymptotic giant branch (AGB) stars provides metals and dust to the interstellar medium (ISM). In our current understanding, mass loss occurs through dust-driven winds originating from the extended atmospheres of these stars. State-of-the-art simula- tions show that large convective cells play an important role, but recent observations at milliarcsecond resolution with ALMA have shown that the conditions in the extended atmospheres might be different than predicted by the models.
Low-frequency observations of evolved stars with the Square Kilometer Array (SKA) and the next- generation Very Large Array (ngVLA) will make it possible to study the critical outer regions of the extended atmospheres where dust forms and is accelerated in a novel way. With the high resolution and sensitivity of upcoming observatories such as SKA, we can use the continuum emission to constrain atmospheric density and temperature structures at larger distances from the star. Also, simultaneous observations of SKA, ngVLA, and ALMA will produce wide-range multi-wavelength data for various radii of the extended atmosphere, enabling us to test and constrain theoretical models in a way that was not possible before. With the large field of view of SKA, we can further study the temporal evolution of evolved star atmospheres and dust-forming regions.
In this presentation, I will discuss the observable features of the upcoming SKA observatory, the unique opportunities for SKA to image AGB stars, and how multiwavelength observations from SKA and ALMA can enhance the detailed study of evolved stars’ atmospheres.
