COMMISSION J: Radio Astronomy(November 2020 – May 2023)
Edited by Nario Kuno (University of Tsukuba)
Activity of meetings
VLBI Consortium Symposium 2019: VLBI Crosses National Borders
Date: Nov. 16th-17th, 2020 : Online meeting
The content of discussions by the VLBI Future Planning Working Group, which wasestablished in response to last year's discussions, and future visions from various perspectives
were discussed intensively to explore and share the future of VLBI throughout the community.

Japan Radio Astronomy Forum Symposium 2020: Radio astronomy that opens up withextreme performance
Date: Dec. 21st-22nd, 2020 : Online meeting
Japan Radio Astronomy Forum is an organization that represents the radio astronomy
community in Japan. As part of its activities, a symposium is held every year for the purpose of
sharing the science and observation technology of radio astronomy and discussing future plans.
At the symposiums of the last two years, we have held multifaceted discussions over two days,
focusing on technological development that will support future radio astronomy and futurescience in collaboration with other wavelengths and fields. Based on these achievements, thismeeting focused on various "extreme performances" regardless of projects and existingtelescopes, to explore science that can only be done by radio astronomy and new methods torealize it in the entire community.

FY2020 ALMA/45m/ASTE Users Meeting
Date: Jan. 5th-7th, 2021 : Online meetingSubmm single dish JCMT with maximum aperture in the Northern Hemisphere & very
fulfilling focal plane devices - Let's use JCMT!
Date: Jan. 5th-7th, 2021 : Online meeting
In conjunction with the ALMA / 45m / ASTE User's Meeting (January 5-7, 2021 morning),this meeting was held with the purpose of promotion of research using JCMT.

ngVLA Science WG Day3
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Date: Jan. 15th, 2021 : Online meeting
The National Astronomical Observatory of Japan ngVLA Study Group has formed a ScienceWorking Group (SWG) with the community to embody participation in the ngVLA project. In
December, debriefing sessions for galactic objects (Day 1) and extragalactic objects (Day 2) wereheld, respectively. In response to this, the entire joint meeting was held as Day 3.
SKA-Japan Webinar series "Construction finally started! SKA and 10 sciences"
Date: Jan. 27th, Feb. 5th, 12th, 19th, Mar. 2nd, 2021 : Online meeting
The next-generation centimeter-wave telescope SKA (Square Kilometer Array) will be
under construction in 2021 after a long preparation period. Taking this opportunity, SKA-Japan
has decided to plan a total of five webinar series in order to convey the appeal of the SKA projectand its science to the astronomy community. In this series, 10 typical scientific topics that arebeing considered in Japan and abroad and the technologies that accompany them were explained.

Research of star formation using ALMA high frequency band
Date: Mar. 2nd, 2021 : Online meeting
This meeting was held to take a bird's-eye view of the research related to star formation /interstellar phenomena in the ALMA high-frequency band (Band 8/9/10) currently being
conducted in Japan, and to discuss future observation strategies in related communities.

13th East Asian VLBI Workshop 2021
Date: Mar. 2nd-5th, 2021 : Online meeting
In this workshop, the fresh scientific results obtained with VLBI were presented. The latest
update on developments for radio astronomy in South-East Asia and in the world to establish socalled a "Global VLBI Network" were also discussed.

The 21st mm/submm receiver Workshop
Date: Mar. 8th – 9th, 2021 : Online meeting
This workshop was held to create cutting-edge technologies, innovative applications, andexpansion of basic technologies related to ultra-high-sensitivity receivers for millimeter,submillimeter, and terahertz waves. The purposes of this workshop were to provide a place forpeople to gather and discuss the latest information freely and openly, and to further improve
Japan's international competitiveness and driving force, improve development efficiency, and to
expand/inherit the base of basic technological capabilities.

Unsolved problems of astronomy challenged with innovation of (sub)millimeter-wave single
2dish telescopes
Date: Mar. 29th-31st, 2021 : Online meeting
This meeting was held to discuss prospects of new science to accelerate the realization oflarge submillimeter-wave single dish telescope.
Science lecture commemorating retirement of Prof. Tetsuo Hasegawa
Date: Apr. 2nd, 2021 : Online meeting

East Asia SKA workshop 2021
Date: May 26th -28th, 2021 : Online meeting
This workshop was held to advance our SKA-related activity in East Asia. In oral sessions,invited speakers introduced the SKA project and SKA precursor/pathfinder activities. Scientificreview talks and many contributed talks covering diverse topics were also presented. Poster
presentations and breakout discussion to encourage conversations to kick off practicalcollaborations in future were also organized.

Japan SKA Consortium Science Strategy Workshop 2021
Date: Jul. 12th-14th, 2021
Location: National Astronomical Observatory of Japan and Zoom
Square Kilometre Array (SKA) is next generation radio interferometer which has been
constructing in Australia and South Africa by international collaboration. The construction ofSKA Phase 1 started this year and scientific operation will start in the late 2020s. This workshop
was held to share the policy of access to scientific outputs by SKA and discuss the priority ofscience goals.

ngVLA-J Development Days 2021
Date: Jul. 15th, 16th, 2021 : Online meeting
NAOJ established the NAOJ ngVLA Study Group in FY2019 to consider and plan with
NRAO a possible contribution from Japan to the development, construction and operations ofngVLA. In these initial 2 years, the Study Group has progressed in the discussion with NRAO
and other prospective international partners and started some initial development studies basedon the know-how acquired by ATC and the ALMA Project during the construction and operationsof ALMA. This meeting was held to share the technical concept of ngVLA with the JapaneseCommunity and report on the progress and technical achievements in these 2 years. The
workshop covered topics related to frontend, cryogenics, time/freq distribution, fabrication andmechanical design, and computing.
3Radio Astronomy Future Plan Review Symposium 2021
Date: Jul. 31st, 2021 : Online meeting
At this symposium, representatives of the future plans for the field of radio astronomy, whosubmitted the LoI (Letter of Intent) to Master Plan 2023, gave lectures on their future plans. The
purpose of this symposium was to deepen the community's understanding of the proposed planand to solicit opinions from the community.

Radio/Interferometer summer school
Date: Sep. 16th, 17th, 21st, 22nd, 24th, 2021 : Online meeting

ALMA workshop: Cold outflows near and far: crossroads of our current understandings
Date: Nov. 1st - 2nd, 2021 : Online meeting
This workshop was held to review recent findings on outflows (observed by ALMA) foundon various astronomical scales from protostars to distant galaxies and to deepen theirunderstanding of their properties.

Linking the science of large interferometers in the 2030s
Date: Nov. 30th - Dec. 1st, 2021 : Online meeting
The goals of this workshop are to (1) identify scientific synergies between future large
interferometers, SKA and ngVLA, and their synergies with current facilities such as ALMA andVLBI collaborations, (2) discuss the future science landscape with large interferometers (ALMA,VLBI, SKA, ngVLA) for the Japanese community in the 2030s and beyond.

VLBI Consortium Symposium 2021: Know the current location of domestic VLBI
Date: Dec. 2nd – 4th, 2021
Venue: National Astronomical Observatory of Japan (Mitaka) and online
At the symposium, the specific activities that are currently underway were reported, andshared and discussed the status of activities within the community. In addition, while deepening
these discussions, the research plans of the VLBI community in Japan in collaboration withastronomical research, geodesy research, and technological development research were discussed.

FY2021 ALMA/45m/ASTE Users Meeting
Date: Dec. 14th, 16th, 21st, 2021 : Online meeting

ALMA workshop: Science of mm/submm VLBI with ALMA
Date: Dec. 20th, 22nd, 2021 : Online meeting4The ALMA workshop was held to discuss science by millimeter/submillimeter wave
VLBI. At the workshop, science that cannot be achieved by the current VLBI in thecm/mm band, but is made possible only by millimeter/submillimeter VLBI observations
with ALMA was discussed.
Black Hole Astrophysics with VLBI 2022Date: Feb. 7th – 9th, 2022 : Online meeting
The accretion flow, jet wind, and black hole, were discussed focusing on VLBI highresolution observations and theories, including the Event Horizon Telescope and the East AsianVLBI network.

The 22nd mm/submm receiver Workshop
Date: Feb. 21st - 22nd, 2022 : Online meeting
This workshop was held to create cutting-edge technologies, innovative applications, andexpansion of basic technologies related to ultra-high-sensitivity receivers for millimeter,
submillimeter, and terahertz waves. The purposes of this workshop were to provide a place forpeople to gather and discuss the latest information freely and openly, and to further improve
Japan's international competitiveness and driving force, improve development efficiency, and toexpand/inherit the base of basic technological capabilities.

Radio Astronomy Consortium Symposium 2021
Date: Mar. 7th-8th, 2022 : Online meeting
The primary purpose of this year's Radio Astronomy Consortium Symposium was to return
to its original purpose and share the latest achievements in each of Japan's wide-ranging radio
astronomy fields.

East Asian ALMA Development Workshop 2022Date: Mar. 9th-10th, 2022 : Online meeting
The main topic of this year was future of Science Archive. Improvements to ALMA Science
Archive is one of the key development items for the success of ALMA in the era of 2030 as
discussed in ALMA Development Road Map.

ALMA workshop: Synergies between ALMA and wide-field high-cadence multiwavelength surveys
Date: Mar. 28th – 30th, 2022 : Online meeting
This workshop was held to discuss synergies between ALMA and the ongoing and future5

surveys in the space, time, and energy (i.e., wavelength) domains, such as those with HSC/PFS
at opt/NIR wavelength, the CMB surveyors (e.g., LiteBIRD, PolarBear), and those from
SKA1/ngVLA.
SKA-precursor ISM-WS 2022
Date: Jun. 27th-28th, 2022
Venue: National Astronomical Observatory of Japan (Mitaka)
This workshop was held for the purpose of comprehensively studying the research resultsof MeerKAT and ASKAP, learning how to handle data, and discussing interstellar matter researchthat should be promoted in the SKA era.

ngVLA community meeting
Date: Oct. 10th-19th, 2022: Online
This meeting was held to report to the community on the progress of ngVLA in Japan andoverseas, the composition of the SWG and future plans, and to receive opinions.

Examination of science developed by centimeter wave observation using Fukui Universityof Technology 10m antenna
Date: Nov. 16th-17th, 2022
Venue: Fukui University of Technology
The purpose of this meeting is what kind of science can be developed by taking advantage ofthe characteristics of Fukui University of Technology's 10m antenna.

The 23rd East Asia Submillimeter-wave Receiver Technology Workshop
Date: Dec. 14th – 15th, 2022
Venue: RIKEN
This meeting was held to discuss research and development in the millimeter wave andterahertz wave regions, thereby promoting mutual development and technical and humanexchanges.

The international conference “A half-century of millimeter and submillimeter astronomy:
Impact on astronomy/astrophysics and the future”
Date: Dec. 15th- 18th, 2022
Venue: Miyakojima, Okinawa
The purpose of this meeting was to review the scientific achievements over the past decades,
to discuss the prospects for future research, and to look ahead to the future direction of6

development of radio astronomy through lectures and presentations on a wide range of scientificfields from stellar/planetary to cosmological scales, including observational instruments.
FY2022 ALMA/45m/ASTE Users Meeting
Date: Dec. 20th, 21st, 2022 :Venue: National Astronomical Observatory of Japan (Mitaka) and Online

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VLBI Consortium Symposium 2022: VLBI Changes for the Next Decade
Date: Dec. 23rd – 25th, 2022
Venue: Tohoku university and online
At the symposium, new policies for the VLBI community in line with the acceleratingchanges in the research environment was discussed.

The international conference “Black Hole Astrophysics with VLBI 2023”
Date: Feb. 6th- 8th, 2023
Venue: National Astronomical Observatory of Japan (Mitaka)
The purpose of the workshop is to have an opportunity for intensive overviews of newadvances in BH astrophysics using VLBI and other state-of-the-art instruments, discuss various
perspectives, and inspire the next research ideas of each participant.

East Asian ALMA Science Workshop 2023
Date: Feb. 14th, 17th, 2023
Venue: New Taipei City, Taiwan
The annual East Asian ALMA Science Workshop serves as a forum to exchange anddiscuss new and exciting scientific results obtained with ALMA, new ideas for future
projects, and new proposals for the upcoming cycle 10.

SKA Japan workshop 2022
Date: Mar. 7th-9th, 2023
Venue: National Astronomical Observatory of Japan (Mitaka)
The purposes of this workshop are followings:
・Based on the full-scale operation of the preceding aircraft, discussion of science with an eye tothe initial scientific operation of SKA1
・Research presentations by young researchers active in the SKA era
・Discussion on a system in which NAOJ and universities participate in close scientific andtechnical cooperation
7・Discussion of strategies for participation in large-scale survey observation projects by theinternational community
ALMA workshop on Dusty Star-Forming Galaxies
Date: Mar. 7th – 10th , 2023
Venue: National Astronomical Observatory of Japan (Mitaka) and Online
The workshop was held to explore the current status and future exploitation of the large
spectroscopic samples (50~100 sources) of distant dusty galaxies, especially of the UK-Japanese
Herschel-selected ALMA BEARS spectroscopic redshift program (Urquhart+2022, Bendo+2023,Hagimoto+subm.).

Radio Astronomy Consortium Symposium 2021
Date: Mar. 27th-28th, 2023
Venue: National Astronomical Observatory of Japan (Mitaka) and Online
The purpose of this symposium was to review the observational results of ALMA over thepast 10 years, share the latest results, taking into account the observation results and development
achievements of related instruments, and discuss the future of radio astronomy in the 2030s.

ngVLA Joint Science Working Group
Date: Mar. 29th, 2023
Venue: National Astronomical Observatory of Japan (Mitaka) and Online
Two years ago, the ngVLA-J Science Working Group met several times to discuss sciencecases. This meeting wea held for the purpose of updating the science that has been proposed so
far and soliciting new ideas.

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