The East-Asian VLBI Network - Seoul National Universityastro1.snu.ac.kr/eama10/20160927_EAMA10/13.Shen... · • 2008 March 20-22: 1st EA VLBI WS in Shanghai • 2009 March 18-20:

The East-Asian VLBI Network

Zhi-Qiang Shen (沈志强)

Shanghai Astronomical Observatory (SHAO)

Chinese Academy of Sciences

Hideyuki Kobayashi (NAOJ), Kiyoaki Wajima (KASI),

Kenta Fujisawa (Yamaguchi Univ.), Wu Jiang (SHAO)

The 10th East Asian Meeting on Astronomy (EAMA10)

2016 September 26-30 @ Seoul National University, Seoul, KOREA

Outline

0. A bit of history

1. Current status of EAVN

2. Recent progress

3. Future plan

Outline

0. A bit of history

1. Current status of EAVN

2. Recent progress

3. Future plan

x = u sina

V1V2

b

V1 V2

telescope 1 telescope 2

q

s0

s0

u

a

u = bcosq b×s0

dldmemlIAevu vmulii )(2),(),( V

spatial resolution: ~l/b

spatial resolution: ~l/D

1967 First VLBI Experiments in USA and Canada

4

Single Dish Interferometer

Global VLBI Station Distribution

5 Not a complete list!

VLBA

EVN

VLBA Ten 25m Antennas,

327 MHz - 86 GHz

6

7

European VLBI Network (EVN)

7

East Asian VLBI Network • 2003 Nov. 3-5: Preparation Committee (PC) was formed

during 1st regional millimeter-VLBI workshop in Shanghai

– PC meeting during the AP-RASC’04 in Weihai

• 2004 Oct. 18-22: East Asia VLBI Consortium was organized

during the EAMA6 in Seoul

– Chair: H. Kobayashi (Japan)

– Co-Chair: M. H. Choi (Korea)

– Secretary: Z.-Q. Shen (China) 8

Responsibility of

EA VLBI Consortium

• Organize VLBI observations in east Asia

region with the existing VLBI facilities

• Exchange information of VLBI technique

developments

• Promote education and training programs

(ex. Summer/winter schools)

9

East Asian VLBI Network • 2005 Nov. 10-12: (J-K) VLBI Symposium at Ishigakijima

• 2006 March 7: 2nd EACOA meeting in Tokyo

• 2006 May 22-23: 2nd East Asia Millimeter-VLBI Science

Workshop in Nanjing

• ……

• 2010 Oct. 13: EA VLBI Consortium Meeting during the

EAMA8 in Shanghai

• ……

• 2013 June: The EAVN “Tiger Team”, chaired by Y. Hagiwara

of NAOJ then and now K. Wajima of KASI, was organized

– To coordinate VLBI test observations

– To proceed data reduction of test observations

– To pave the road for future regular operation and open-use of the EAVN

10

East Asian VLBI Network

11

Outline

0. A bit of history

1. Current status of EAVN

2. Recent progress

3. Future plan

Existing VLBI stations in 2005

• Japan(11)

– VERA(4), Kashima, Tsukuba, Yamaguchi,

Nobeyama, Usuda, Tomakomai, Gifu

• Korea(1)

– Taejun, (+KVN (3))

• China(2)

– Shanghai, Urumqi, (+Beijin, Kumming)

22 GHz: 8 stations

43 GHz: 7 stations

13

Japanese VLBI Network (JVN) led by Japanese Universities

• Collaboration

– NAOJ (VERA)

– Universities (Hokkaido,

Ibaraki, Tsukuba, Gifu,

Osaka-Pref, Yamaguchi,

Kagoshima)

– JAXA, NICT, GSI

• Specifications

– 13 telescopes (11m ~ 64m)

• 6~7 active telescopes

– Baseline 50 - 2500 km

– Frequency 6.7/8/22 GHz

JVN 13 Telescopes 14

• Specifications

– 3 telescopes (21m)

– Baseline 300~500 km

– Frequency 22, 43, 86,

129 GHz (Simultaneous

Multi-Frequency Obs.)

15

Korean VLBI Network (KVN)

2460

2158

3249

1114

2476

1920

Chinese VLBI Network (CVN)

1993(25m)

1987(25m)

2006(50m)

2006(40m)

2006(correlator)

Baseline length: 1115km to 3249km (Coverage: E-W:34° S-N:18°)

2012(65m)

16

Science 2008 Dec. 5

17

Ogasawara 20 m Iriki 20 m

6.7 GHz

8 GHz

22 GHz

43 GHz

Sheshan 25 m Kunming 40 m Kashima 34 m Ishigakijima 20 m

Takahagi 32 m

Tianma 65 m

Mizusawa 20 m

(Image Credit: Reto Stöckli, NASA Earth Observatory)

Hitachi 32 m

Nanshan 26 m

Ulsan 21 m Usuda 64 m Gifu 11 m Tamna 21 m Miyun 50 m Yonsei 21 m Sejong 22 m

Yamaguchi 32 m

KASI/KJJVC

SHAO/DiFX

EAVN: Specifications • Number of (potential) telescopes: 19 (16 telescopes have

participated in test observations one or more times) – Korea: 4, China: 5, Japan: 10

• (Possible) frequency coverage: – 6.7 GHz (12 stations), 8 GHz (15), 22 GHz (16), 43 GHz (10)

• (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) – 0.7 mas (43 GHz; Ogasawara – Tianma)

• 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: ≧ 2 Gbps (= 512 MHz BW) • (Currently-used) correlator:

– KJCC (Korea): KJJVC and DiFX – SHAO (China): DiFX

19

Total effective aperture and

longest baseline length

EAVN VLBA EVN

No. of Stations ２０ １０ １２

Longest Baseline

Length (km)

5,000 8,000 2,000 - 8,000

Effective Aperture

@8 GHｚ (m2)

9,000 3,700 9,800

Effective Aperture

@22 GHz (m2)

4,900 3,200 4,900

Effective Aperture

@43 GHz (m2)

1,400 2,900 1,800

20

• 22 GHz

• 10-hour duration

• array of 16 telescopes

• Beam size: 0.6 mas

Examples of (u, v) Coverage

δ = +60 deg δ = +30 deg

δ = 0 deg δ = –29 deg

δ = +60 deg

21

KJCC

Executive Board

Daejeon Correlator DiFX Correlator on HPC 22

DiFX correlator at SHAO

e-transfer links

400 CPUs, 432 TB storage, built

in 2014.12

• Astrophysics (200 CPUs). serve for CVN, EAVN (FT), international VLBI.

• Geodesy (200 CPUs). serve for CVN, IVS standard correlator.

• Features support MKIV, Mark5B, KVN5B, VDIF raw data format;

support pulsar gating, multi-phase center, zoom spectrum etc.

23

Outline

0. A bit of history

1. Current status of EAVN

2. Recent progress

3. Future plan

EAVN: Fringe Test Experiments

• 8 times during 2013 September — 2015 February: 2013 (2), 2014 (5), 2015 (1)

• Stations involved: 4 (2014 Sep) – 11 (2013 Sep), 16 stations have participated in fringe tests one or more times (CN: 4, KR: 4, JP: 8)

• Observation duration: 1 hour (typical)

• Observing Frequency: 8, 22 GHz

• Observing mode: 256 MHz bandwidth (16 MHz×16 ch), data recording rate of 1 Gbps

• Polarization: RHCP (8 GHz), LHCP (22 GHz)

• Correlator: KJJVC (KASI), DiFX (KASI/SHAO)

25

EAVN: List of Fringe Test Observations # Date Frequency Antenna Source

8 22 KVN+ VERA JVN CVN

YS UL TN SJ MZ IR OG IS YM TH HI TK SH TM UR KM

1 2013 Sep 24 ■ ● ● ● ● ● ● ● ● ● ● ●

■ ● ● ● ● ● ● ● ● ●

2 2013 Nov 22

3 2014 Jan 28 ■ ● ● ● ● ● ▲ ● ●

■ ● ● ● ▲ ▲ ▲ ▲ ● ● ●

4 2014 May 27 ■ ● ● ● ● ● ● ● ● ● 0528+134, DA 193

■ ● ● ● ● ● ● ● ● ● ●

5 2014 Sep 16 ■ ● ● ● ● 3C 273, W3OH

6 2014 Oct 18 ■ ● ● ● ● ● ● 3C 273, W49N

7 2014 Nov 11 ■ ● ● ● ● ● ● ● ● 3C 345, W49N

8 2015 Feb 12 ■ ● ▲ ● ● ● BL Lac, 3C 454.3

26

EAVN: Observations since Dec 2015 # Date Frequency Antenna Target

8 22 43 KVN VERA JVN CVN ATCA

YS UL TN MZ IR OG IS YM TH HI TK TM KM NS AT

1 2015 Dec 13 ■ ● ● ● ● ● ● ● ● ● 4C 39.25

2 2016 Mar 20 ■ ● ● ● ● ● ● ● ● ● M87

3 2016 Mar 21 ■ ● ● ● ● ● ● ● ● M87

4 2016 Sep 13 ■ ● ● ● ▲ ▲ ▲ ▲ ● 1633+382 (2 Gbps

Fringe Test)

5 2016 Sep 26 ■ ● ● ● ● ● ● ● ● ● 3C 273, M84, M87, RT Vir

6 2016 Sep 26 ■ ● ● ● ● ● ● ● ● (BL Lac, 3C 454.3)

• Total observing time: 36 hours (6 sessions)

• Number of telescopes: 15 (KR: 3, CN: 3, JP: 8, AU: 1)

• Frequency: 8 GHz (1), 22 GHz (2), 43 GHz (3) – Part of observations were conducted in collaboration with the KaVA AGN

Large Program 27

Preliminary Results (2015 December 13) • Source: 4C 39.25; telescope: VERA Mizusawa, KVN Ulsan, Tianma, Kunming

• τ = 60 s, bandpass correction NOT applied, a priori calibration NOT applied, amplitude correction by ACCOR, –180°< φ < +180°

MIZ

– U

LS

MIZ

– K

UN

U

LS –

KU

N

MIZ

– T

IA

ULS

– T

IA

TIA

– K

UN

Raw data ACCOR, FRING applied

MIZ

– U

LS

MIZ

– K

UN

U

LS –

KU

N

MIZ

– T

IA

ULS

– T

IA

TIA

– K

UN

28

Preliminary Results (2016 March 20)

• First 43 GHz image of M87 by EAVN on 2016 Mar 20

– Non-cooled receiver was used at Tianma station

– ‘Indirect’ amplitude scaling was applied to the Tianma’s visibilities

KaVA KaVA+Tianma

DR = 3238 σ = 0.24 mJy/b

DR = 3540 σ = 0.22 mJy/b

(Image courtesy: Dr. Kazuhiro Hada (NAOJ)) 29

Tianma-65m Q band fringes Cryogenic Rx VLBI Fringes to Tianma-KVN (2016 Sept.13)

30

Publ.Astron.Soc.Japan 66, 31 (2014)

31

The First Results of EAVN (6 sessions between 2010 and 2011)

Shanghai 25m

VERA 20m x 4

Ibaraki 32m (Hitachi) Usuda 64m

Yamaguchi 32m 32

33

Different morphological categories: linear, elliptical, complex etc (Fujisawa et al. 2014)

006.79-00.25 031.28+00.06 009.61+00.019

Proper motions of CH3OH maser sources (Sugiyama et al. 2015)

G006.79-00.25

Outline

0. A bit of history

1. Current status of EAVN

2. Recent progress

3. Future plan

Short- and Mid-Term Plan

9/10

Year 2014 2015 2016 2017 2018

Act

ion

s

・5-time fringe tests done ・FTP data transfer test

・Further fringe tests ・Imaging tests, performance evaluation

・Imaging tests ・Science commissioning observations at 8/22 GHz ・Fringe tests at 6.7/43 GHz

・(Late 2017) Risk-shared open-use at 8/22 GHz ・Performance evaluation and science commissioning at 6.7/43 GHz

・(Late 2017) Risk-shared open-use at 6.7/8/22/43 GHz ・Performance evaluation for extending observation modes (2-pol., wide-band, etc.)

Freq. 8/22 GHz 8/22 GHz 6.7/8/22/43 GHz 6.7/8/22/43 GHz 6.7/8/22/43 GHz

Pu

rpo

ses

・Fringe detection from some telescopes in EAVN

・Evaluation of array performance and imaging capability

・Evaluation of array performance and array operation commissioning ・Performance evaluation at 6.7/43 GHz

・Initial scientific outputs from EAVN ・Confirmation of performance at 6.7/43 GHz

・Regular operation of EAVN ・Conformation of performance for various observation modes

35

Short- and Mid-Term Plan

• Re-organization of the Tiger Team and re-definition of tasks

– Re-organization of the task force for imaging tests (and the future open-use operation)

– Brushing up the items for imaging tests

• Fringe tests and imaging tests at 6.7 GHz

– EAVN observations at 6.7 GHz was carried out using the VSOP Terminal (with a recording rate of 128 Mbps)

• Fringe tests and imaging tests with the data rate of 2 Gbps

– The first 2 Gbps fringe test was conducted on 2016 September 13

• Set of goals of science objective

– Organization of science sub-WGs on the basis of scientific activities by KaVA sub-WGs

• Acquirement of budget for regular operation 36

Long-Term Plan

• Collaboration with the Australian LBA ( short- or mid-term agenda?)

• Collaboration with the FAST – Time schedule of installation of the VLBI backend system

– VLBI observations at 1.6/2 GHz?

• Collaboration with the Thai VLBI Network (TVN) – Good to connect between EA and OZ

– Available in 2020+? (Boonrucksar Soonthornthum’s talk)

• In synergy with ALMA (mm/sub-mm) amd SKA 37

EAO

EAVN?

(Paul Ho’s talk)

38

East Asia VLBI Workshop • 2008 March 20-22: 1st EA VLBI WS in Shanghai

• 2009 March 18-20: 2nd EA VLBI WS in Seoul

• 2010 April 22-24: 3rd EA VLBI WS in Kagoshima

• 2011 April 18-20: 4th EA VLBI WS in Lijiang

• 2012 May 30 – June 1: 5th EA VLBI WS in Taipei

• 2013 June 17-19: 6th EA VLBI WS in Jeju

• 2014 Aug. 20: 7th EA VLBI WS in Daejeon (as part of APRIM)

• 2015 July 8-10: 8th EA VLBI WS in Sapporo

• 2016 Nov. 7-11: 9th EA VLBI WS in Guiyang

39 39

Thank you for your attention！