Poster Presentation
Evolution of AGN jets with different cosmic-ray composition
Presenter: Yen-Hsing Lin (NTHU)
Active galactic nucleus (AGN) jet feedback is an important mechanism that regulates the evolution of galaxy clusters. However, the composition of AGN jets remains uncertain; they could be dominated by thermal, cosmic-ray proton (CRp), cosmic-ray electron (CRe), or magnetic energy. In this work, we investigate how AGN jets of different cosmic-ray (CR) compositions would impact the process of AGN feedback in galaxy clusters. We performed 3D magnetohydrodynamic (MHD) simulations of AGN jet-inflated bubbles in the intracluster medium (ICM) using the FLASH code. Specifically, we focus on two cases: CRp-dominated jets and CRe-dominated jets, which experience dramatically different strengths of cooling. Contrary to our expectation, the morphology of CRp and CRe jets evolves very similarly because CRe bubbles become thermal energy dominated at an early epoch, resulting in a similar total energy evolution of the two bubbles, which subsequently produce similar bubbles. Besides, our simulations could not reproduce the observed CRe dominated bubbles, suggesting that in-situ acceleration mechanisms of CRs (via shock or turbulence) are important and should be included in future simulations.
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