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Rationale

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Extreme phenomena in the universe are often triggered by the strong gravitational field of black holes (BHs) and surrounding relativistic plasma’s activities. Recent ultra-high spatial resolution observations with VLBI provide new clues to a better understanding of what happens around the BHs.

Hot topics to be presented and discussed in the workshop will be as follows: 

(1) As for Sgr A*, there has been a breakthrough in picturing Sgr A* BH shadow and surrounding photon ring with the Event Horizon Telescope. On the other hand, detailed explorations of the newly arising questions of  "time variability" and "presence/absence of an outflow" of Sgr A* are just beginning. (2) Regarding M87, both observationally and theoretically, there is a growing movement toward understanding the whole picture of the M87 jet by bridging the spatial gap between the BH-shadow and the downstream jet. In this process, much attention is paid to "nonthermal electrons” and "polarization." (3) Multimessenger astronomy is more and more important in BH research. Recent low-frequency radio observations dramatically change the pictures of compact radio transients such as neutron stars and FRB as well as AGN jet lobes in galaxy clusters, both of which will be major targets for future SKA/ngVLA.  (4) Unique developments and experiments for radio telescopes both at high-frequency and low-frequency are underway in the East Asia region.

The purpose of the workshop is to have an opportunity for intensive overviews of new advances in BH astrophysics using VLBI and other state-of-the-art instruments, discuss various perspectives, and inspire the next research ideas of each participant.

This workshop is a continuation of a series of workshops organized by East Asian VLBI community and one of the features of this year’s one is to find a link between low-frequency and high-frequency science.

https://sites.google.com/view/blackholeastrophysicswithvlbi2/%E3%83%9B%E3%83%BC%E3%83%A0

[Invited Speakers; Keywords]

Sean Ressler (UC Santa Barbara); Sgr A* theory, GRMHD

Yuh Tsunetoe (Kyoto Univ); GRRT, Polarized emissions

Michael D. Johnson (Harvard BHI); EHT Sgr A*, ngEHT

Rusen Lu (SHAO); M87 observations at 3mm

Jongho Park (KASI); EAVN, VLBA, M87 polarimetric observations

Christian Fromm (Wurzburg Univ); M87 theory, GRMHD, nonthermal emissions

Hiroshi Nagai (NAOJ); ALMA, AGN winds, nonthermal emissions

Kotaro Niinuma (Yamaguchi Univ); EAVN, JVN, High energy blazars

Teruaki Enoto (RIKEN); Neutron Stars

Kohei Kurahara (NAOJ); AGN radio lobes and galaxy clusters

Bo Zhang (SHAO); VLBI with FAST

BongWon Sohn (KASI); KVN at 230GHz

Ue Li Pen (ASIAA); FRB and BURSTT Project

Kiyoaki Wajima (KASI); EAVN future plans

SOC:

Motoki Kino (Kogakuin Univ/NAOJ, chair), Tomohisa Kawashima (ICRR, co-chair), Kazuhiro Hada (NAOJ), and Takuya Akahori (NAOJ)

LOC:

Takuya Akahori (NAOJ/SKAO, chair), Elika Prameswari Fariyanto (Tokyo Univ/NAOJ), Marie Katsukawa (NAOJ), Akiyo Komori (NAOJ), Kohei Kurahara (NAOJ), Aika Oki (Tokyo Univ/NAOJ), and Hiroki Okino (Tokyo Univ/NAOJ)