Category High Energy Physics and Astrophysics
Event Duration 2022-08-26 - 2022-08-26
Conference Name NCTS Astrophysics seminar
Speaker Yen-Hsing Lin (NTHU)
Content Evolution of AGN jets with different cosmic-ray composition

AGN jet mode feedback is one of the most promising mechanisms for suppressing cooling flows in cool-core (CC) clusters. However, the composition of AGN jets and bubbles remains uncertain; they could be thermally dominated, or dominated by cosmic-ray proton (CRp), cosmic-ray electron (CRe), or magnetic energy.
In this work, we investigate the evolution and impact of AGN jets of different CRp and CRe jets by conducting 3D MHD simulations of AGN jet-inflated bubbles in the intracluster medium (ICM) using the FLASH code.

We find that, counter-intuitively, CRe dominated jets follow a very similar dynamical evolution to that of CRp dominated jets even though the CRe jets suffer significantly stronger synchrotron and inverse-Compton cooling. This is because, as CRe lose their energies, the jet-inflated bubbles quickly become thermally dominated within ~20 Myr, resulting in similar dynamics to CRp dominated bubbles. Our results also suggest that, in order to reproduce the observed population of CRe dominated bubbles, in situ acceleration of CRe by shocks or turbulence within the AGN bubbles is required. 
Sign Up Duration 2022-08-19 - 2022-08-25
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