Poster Presentation
Effects on polarization properties of radio galaxies by magnetized AGN jets
Presenter: Zheng-Xian Hsu (NTHU)
Radio galaxies are a subtype of active galactic nuclei (AGN) generated by supermassive black hole (SMBH) jets. Polarization measurements of the radio lobes could potentially probe the magnetic field geometry and initial magnetization of the jets. Previous polarization observations have found magnetic field aligned with the jet axis; however, the connection between the magnetization of the jets and the observed polarized emission remains poorly understood. In this research, we use 3D magnetohydrodynamic code GAMER-2 to simulate magnetized AGN jets with a toroidal field geometry within an isolated cluster. We perform simulations with different jet magnetization, and study their difference in the evolution of field geometry within the lobes and their polarization maps. With more magnetized jets, we find an enhancement of the magnetic pressure within the lobes, which affects the expansion of the lobes. However, our synthetic polarization images show more aligned polarization vectors along the jet axis in the case of unmagnetized jets. This suggests that AGN jets originally launched from the vicinity of the SMBH may not retain a significant toroidal magnetic field before they reach kpc scales.
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