VLBI Activities in East Asia andFirst-Year Achievements of Open Use Programwith the East Asian VLBI Network (EAVN)
Contents
Introduction to EAVN
Recent Updates
Status of EAVN Open-Use Program
Short- and Mid-Term Agenda
Summary

WAJIMA, Kiyoaki (轮岛 清昭)(KASI; awarded PhD degree at Ibaraki University)
2019年9月24日 東アジアVLBIワークショップ

EAVN: Specifications (as of 2019 Sep 24)• Number of (potential) telescopes: 19 (16 telescopes haveparticipated in previous EAVN observations one or more times)

Tamna 21 m

Miyun 50 m

KASI/DHC

Sejong 22 m

Yonsei 21 mUlsan 21 m

Gifu 11 m

Usuda 64 m

Mizusawa 20 m

– Korea: 4, China: 5, Japan: 10• (Possible) frequency coverage:– 6.7 GHz (11 stations), 8 GHz (14), 22 GHz (15), 43 GHz (11)

• (Expected) angular resolution:Nanshan 26 m

Takahagi 32 m

– 2.4 mas (6.7 GHz; Ogasawara – Kunming)– 1.5 mas (8 GHz; Ogasawara – Nanshan)– 0.6 mas（22 GHz; Ogasawara – Nanshan)– 0.3 mas (43 GHz; Ogasawara – Nanshan)• Sensitivity for 7-σ fringe detection (τ = 60 s, B = 256 MHz):

Tianma 65 mHitachi 32 m

– 1.6 mJy (8 GHz; Tianma – KVN)
– 9.5 mJy (22 GHz; Tianma – KVN)

• (Expected) recording rate: ≧ 1 Gbps (= 256 MHz BW)• (Currently-used) correlator:
Kunming 40 m

Sheshan 25 m

SHAO/DiFX

Yamaguchi 32 m

Ishigakijima 20 m

Iriki 20 m

Nobeyama 45 m

– KASI (Korea): Daejeon Hardware Correlator (DHC) and DiFX
6.7 GHz– SHAO (China): DiFX
8 GHz

2/12

(Image Credit (ground photograph): Reto Stöckli, NASA Earth Observatory)

22 GHz43 GHz

Ogasawara 20 m

EAVN: Specifications (as of 2019 Sep 24)• Number of (potential) telescopes: 19 (16 telescopes haveparticipated in previous EAVN observations one or more times)– Korea: 4, China: 5, Japan: 10• (Possible) frequency coverage:– 6.7 GHz (11 stations), 8 GHz (14), 22 GHz (15), 43 GHz (11)

• (Expected) angular resolution:– 2.4 mas (6.7 GHz; Ogasawara – Kunming)– 1.5 mas (8 GHz; Ogasawara – Nanshan)– 0.6 mas（22 GHz; Ogasawara – Nanshan)– 0.3 mas (43 GHz; Ogasawara – Nanshan)• Sensitivity for 7-σ fringe detection (τ = 60 s, B = 256 MHz):– 1.6 mJy (8 GHz; Tianma – KVN)
– 9.5 mJy (22 GHz; Tianma – KVN)

• (Expected) recording rate: ≧ 1 Gbps (= 256 MHz BW)• (Currently-used) correlator:– KASI (Korea): Daejeon Hardware Correlator (DHC) and DiFX– SHAO (China): DiFX
2/12

Recent Updates (since the last EAVW)• Shutdown of Kashima 34 m telescope• Approval of the E-KVN project (2020 – 2027) (Taehyun-san’stalk on Sep 24)– New 21-m telescope at northeast of Korea– High-accuracy antenna surface up to 230 GHz• Receiver upgrade– Installation of new wideband receivers at Q-band (35 – 50 GHz) andW-band (85 – 116 GHz) at KVN Yonsei (2019 Sep)
– Installation of K/Q simultaneous reception system at all VERA stations(test observations in 2019 Sep)
– Development of K/Q/W simultaneous reception system at Nobeyama(Imai-san’s talk on Sep 26)• EAVN-hi experiments (Matsushita-san’s talk on Sep 24)– VLBI fringe tests at 230 GHz using EA telescopes• Activities in Southeast Asian countries– Malaysia, Thailand, Indonesia (Zamri-san, Phrudth-san, and Taufiqsan’s talks on Sep 25)
3/12

Launch of EAVN Open-Use Program• EAVN open-use program has been launched from the2018B semester on the basis of MoA between 4
institutes (KASI, NAOJ, SHAO, and XAO)

4/12

(MoA signing ceremony at the last EAVW on 2018 September )Status of EAVN Open Use• EAVN started the open-use program from 2018B
semester– Frequency: 22, 43 GHz– Observation time: 100 h/semester (~ 4.5 months)– Correlator: Daejeon Hardware Correlator at KASI
Semester

Maximum
observation timeOversubscription Rate(# of accepted/submitted proposals)

Telescope

2018B

100 h

1.08 ( 5/ 6)

KaVA, Nobeyama, Tianma (9)

2019A

100 h

2.35 ( 8/16)

KaVA, Nobeyama, Tianma, Nanshan (10)

2019B

250 h

1.54 (17/24)

KaVA, Nobeyama, Tianma, Nanshan (10)

2020A

500 h

5/12

KaVA, Nobeyama, Tianma, Nanshan,Takahagi (11)2018B
2019A

Summary of KaVA/EAVN Observations

SemesterCategory

Total observing time (# of observing epochs)

KaVATianma

NanshanNobeyama

KaVA Open Use152.5 (23)–––

EAVN Open Use

92.0 (14)92.0 (13)LP (AGN)46.0 ( 7)

LP (SFR)

96.0 (12)LP (Evolved stars)

43.0 (14)12.0 ( 4)

12.5 ( 5)Performance test

32.0 ( 2)–––Total

461.5 (71)104.0 (17)26.5 ( 7)38.0 ( 5)KaVA Open Use

48.0 ( 9)–––EAVN Open Use

79.5 (13)76.0 (13)61.5 ( 8)46.0 ( 8)

LP (AGN)180.0 (22)161.0 (19)47.0 ( 6)

LP (SFR)

72.0 ( 9)LP (Evolved stars)

48.0 (12)KaVA/EAVN DDT

116.0 (16)21.5 ( 4)

6.0 ( 1)

Performance test

75.0 ( 7)51.0 ( 6)15.0 ( 3)

Total

618.5 (88)309.5 (42)129.5 (18)38.0 ( 5)14.0 ( 2)46.0 ( 8)Summary of KaVA/EAVN Observations• Total observing time (and # of observing epochs)
for KaVA/EAVN sessions in the 2018B and 2019A
semesters– KaVA: 1080.0 h (159) (incl. GOT 372.0 h / LP 485.0 h)– Tianma: 413.5 h (59) (incl. GOT 168.0 h / LP 173.0 h)– Nanshan: 156.0 h (25) (incl. GOT 61.5 h / LP 73.5 h)– Nobeyama: 96.0 h / 84.0 h (13)– Hitachi (JP): 12.0 h (2) (EAVN TT)– Yamaguchi (JP): 12.0 h (2) (EAVN TT)– Medicina (IT): 28.5 h (9) (GOT 13.0 h / LP 15.5 h)– Noto (IT): 30.0 h (9) (GOT 13.0 h / LP 17.0 h)– Sardinia (IT): 29.0 h (10) (GOT 6.0 h / LP 23.0 h)– Badary (RU): 6.0 h (1) (GOT)7/12

EAVN AGN Campaign• Tracing trajectory of each jet component in M87
precisely• Relation between the physical state of thesupermassive black hole and jet launch/acceleration
mechanisms

8/12(EAVN Collaboration, in prep.)(EHT Collaboration 2019, ApJL, 875, L4)

Short-Term Agenda
EAVN Overview

Tamna 21 m

Miyun 50 m

KASI/DHC

Sejong 22 m

Yonsei 21 m

Ulsan 21 m

Gifu 11 m• New addition: Takahagi 32 m (22 GHz)• Timeline:

EAVN AGN Campaign

Nanshan 26 m

Compact Receiver

Tianma 65 m

Usuda 64 m

Mizusawa 20 m

– Announcement: 2019 September– Proposal submission deadline: 2019 November 1– Proposal review (screening): 2019 November– Announcement of review results: 2019 December– Term of observation: 2020 January – 2020 June

Takahagi 32 m

Hitachi 32 m

Summary
Kunming 40 m

5/9Sheshan 25 m

SHAO/DiFX

Yamaguchi 32 m

Ishigakijima 20 m

Iriki 20 m

(Image Credit (ground photograph): Reto Stöckli, NASA Earth Observatory)

Nobeyama 45 m

6.7 GHz
8 GHz
22 GHz43 GHzOgasawara 20 m

Short-Term Agenda• Open-use program at 6.7 GHz from the 2020B
semester– 8 telescopes
Yamaguchi)(VERA,KVN-Ulsan,Tianma,Hitachi,• Open-use program with dual-polarization mode
(2020B or 2021A)• Launch of the new EAVN Large Program from the2020B semester

10/12

Mid-Term Agenda

11/12

Summary• Introduction to the East Asian VLBI Network (EAVN) andone-year achievements of the EAVN open-use program– Total observing time of 1,080 hours (159 epochs) by EAVN

• Introduction to recent progresses and updates of VLBIrelated activities in (South)East Asian countries• Proposal submission deadline for EAVN 2020A semester:
2019 November 15, 08:00 UT (online submission)– Refer to EAVN website: http://eavn.kasi.re.kr/

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