The impact of stellar mass-loading on AGN jet feedback in galaxies

Feedback by accreting supermassive black holes is central to suppressing star formation in early-type galaxies. Active galactic nucleus (AGN) jets are thought to be one of the key heating mechanisms for the galaxy gas reservoir. However, these highly collimated jets must be decelerated inside the galaxy if they are to disperse their energy into the interstellar medium. Stellar entrainment from stellar winds, or stellar mass-loading, is one process that facilitates feedback by slowing down the jet and allowing it to couple to the interstellar gas. Previous work has focused on the role of evolved stars (red supergiants and AGB stars) in stellar entrainment of jets. This focus has been because of their high mass-loss rates via the stellar wind. Here, we explore the role of main sequence stars in mass-loading, which have weaker stellar winds but are comparatively ubiquitous. In so doing, we focus on less powerful—but much more common—jets from low-luminosity AGN. As a precursor to magneto-hydrodynamic simulations, we present analytic calculations of mass-loading rates for evolved main sequence stellar populations. We estimate the maximum jet power that can be decelerated by early-type galaxies of a given mass and stellar population. Thus, we establish the baseline conditions required for jets to produce feedback. Our project will help unveil the conditions and mechanisms by which radio mode feedback operates in galaxies and suppresses star formation.