Oral Presentation

Resolving the jet collimation and gamma-ray emission region in blazar Mrk 501

Author(s): Shoko Koyama, Keiichi Asada, Masanori Nakamura, Wen-Ping Lo (ASIAA), Motoki Kino, Kazuhiro Hada, Hiroshi Nagai (NAOJ), Kazunori Akiyama (MIT), Guang-Yao Zhao (KASI), Marcello Giroletti (INAF/IRA), David Paneque (MPIfP), Eduardo Ros (MPIfR) et al.

Presenter: Shoko Koyama (ASIAA)

Probing the detailed structure of the inner part of the relativistic jets is a fundamental issue for understanding jet launching and collimation mechanisms. High-resolution VLBI observations have revealed the limb-brightened structure and allowed to study the jet collimation profile and discriminate the jet foot point of the nearby radio galaxy M87. However, intensive studies have not been performed for blazars. Multi-frequency VLBI analysis have revealed parabolically collimated structure, from ~10^3 to ~10^5 Schwarzschild radii. We will discuss the origin of the relativistic jet, and further compare the jet launching mechanism with M87. We will also present our future prospects with the Event Horizon Telescope observations.