Oral Presentation

Magnetic fields at the jet base of M87

Author(s): Motoki Kino (KASI)

Presenter: Motoki Kino (KASI)

Elucidating the formation mechanism of relativistic
jets in active galactic nuclei is one of the longstanding
challenges in astrophysics.
Although magnetically driven jet models are widely discussed,
an actual value of the strength of magnetic fields at the
jet base is still an open problem.
Hence, we explore the degree of magnetization at the jet base
of M87 by using the observational data of the Event Horizon
Telescope (EHT) at 230 GHz obtained by Doeleman et al (2012).
By utilizing the method of constraining magnetic fields and
particle energies in SSA-thick regions (Kino et al. 2014, 2015),
we find that the magnetically driven jet scenario in M87 is viable
in terms of energetics close to the Innermost Stable Circular
Orbit (ISCO) scale unless the EHT region is fully SSA-thin and
relativistic protons dominated.