Coronal Magnetic Activity in nearby Active Supermassive Black Holes: 井上芳幸 (大阪大)


 日時 2020年12月18日(金) 15:30-17:00
 講師 井上芳幸 (大阪大)  
 題名“Coronal Magnetic Activity in nearby Active Supermassive Black Holes”
 概要などCentral supermassive black holes of active galactic nuclei (AGNs) host hot plasma with a temperature of 10<sup>9</sup>K, namely coronae. Like the Sun, black hole coronae are theoretically believed to be heated by their magnetic activity. However, such activity has not been observed yet. In this talk, I will report the first clear detection of coronal magnetic activity in nearby AGNs using ALMA (radio telescopes). The coronal magnetic fields are typically  ∼10
G on scales of ∼40 Schwarzschild radii. The measured magnetic field is weaker than the theoretical expectation, requiring a new corona heating mechanism. I will also discuss particle acceleration processes in the coronae of Seyferts, which may be the production sites of the high energy neutrinos seen by IceCube. Future MeV gamma-ray observations will provide critical tests to our scenario.