Status and future of East Status and future of East Asia VLBI networkAsia VLBI network

H.Kobayashi(NAOJ)H.Kobayashi(NAOJ)2009.3.182009.3.18

East Asia VLBI WS@SeoulEast Asia VLBI WS@Seoul

Current working VLBI stationsCurrent working VLBI stations

Japan(13)Japan(13)• VERA(4), Kashima, Tsukuba, Yamaguchi, NobeyVERA(4), Kashima, Tsukuba, Yamaguchi, Nobey

ama, Usuda, Tomakomai,ama, Usuda, Tomakomai, 　　 Gifu,Gifu, 　　 Uchinoura, Uchinoura, Takahagi, HitachiTakahagi, Hitachi

Korea(3)Korea(3)• KVN (3) KVN (3) Seoul, Ulsan, JejuSeoul, Ulsan, Jeju

China(4)China(4)• Shanghai, Urumqi, Beijin, KummingShanghai, Urumqi, Beijin, Kumming• Shanghai 64mShanghai 64m 　　

-> Possible largest array in the world

East VLBI Network array configuration

Feature of East Asia VLBI networkFeature of East Asia VLBI network

Largest number of VLBI stationsLargest number of VLBI stations• 8GHz 13 stations8GHz 13 stations• 22GHz 19 stations22GHz 19 stations• 43GHz 8 stations43GHz 8 stations

Phase referencingPhase referencing• VERA 2 beam systemVERA 2 beam system• KVN multi-frequency + fast noddingKVN multi-frequency + fast nodding

Good UV coverageGood UV coverage• Minimum baseline length ; 50 kmMinimum baseline length ; 50 km• Maximum baseline length ; 6000 kmMaximum baseline length ; 6000 km

Scientific objectives of EAVNScientific objectives of EAVN Astrometry and phase referencing VLBIAstrometry and phase referencing VLBI

• VERA + KVN : 20m x 7stations @22/43 GHzVERA + KVN : 20m x 7stations @22/43 GHz• JVN + CVN : methanol maser observation JVN + CVN : methanol maser observation

@6.7GHz@6.7GHz Sensitive imaging array @ 8/22 GHzSensitive imaging array @ 8/22 GHz

• JVN+KVN+CVN : >15 stations arrayJVN+KVN+CVN : >15 stations array• Ground array for VSOP-2 (2013 launch)Ground array for VSOP-2 (2013 launch)

Joint array with other networkJoint array with other network• Asian Pacific Telescope with LBAAsian Pacific Telescope with LBA• EVN + EAVN ; powerful global arrayEVN + EAVN ; powerful global array

East Asia VLBI consortium(under East Asia Core

Observatory Association)～ 2004

Japanese VLBI networkIncluding VERA Korean VLBI network

Chinese VLBI network

Assumption of Observation Time Assumption of Observation Time (2010~)(2010~)

EAVN 2,000 H/Y

2,500 2,5001,500

1,000Geodesy

1,000

1,000

KVN5,000 H/Y

VERA5,000 H/Y

Seoul 6,000 H/Y

Mitaka 2,500 H/Y

VSOP-2

Science (Dec. 5,2008)Science (Dec. 5,2008)

Results of VERA measurementsResults of VERA measurements

Sun

S269

Milky way galaxy

Illustration courtesy: NASA/JPL-Caltech/R. Hurt (SSC/Caltech)

NGC 281

NGC 281

ρ oph

S CrtOrion

NGC 1333

Sun neighborhood

VY CMa

Parallax + Proper motion Proper motion

Sgr A

OH43

W49NON2

Kaguya (RISE) missionKaguya (RISE) mission

Precise gravity field of moon

-> cooling time differences between farside and nearside

Takahagi/Hitachi; New VLBI stationTakahagi/Hitachi; New VLBI station

Takahagi/Hitachi

Kashima

Tsukuba

Usuda

１００ｋｍ

５０ｋｍ

２００ｋｍ

Takahagi/Hitachi

32m x 2

6-8GHz

22GHz

Sensitive array with short baselines

See Yonekura’s poster

Simultaneous Multi-Frequency Obs. -Phase Compensation, mm-VLBI

Constructions of three stations were completed on Dec. 2008 !

First fringe between Seoul and First fringe between Seoul and VERA@2008,308dVERA@2008,308d

1993 (25m)

1987(25m)

2006 (40m)

2006(50m)

Chinese VLBI NetworkChinese VLBI Network

2006

CorrelatorCorrelator

4 station software VLBI correlator4 station software VLBI correlator 5 stations hardware VLBI correlator5 stations hardware VLBI correlator

(128MHz bandwidth)(128MHz bandwidth)

e-VLBI (16Mbiteps) for 4 stations in e-VLBI (16Mbiteps) for 4 stations in 10 minutes 10 minutes

VLBI CorrelatorVLBI Correlator

Data reductionData reduction

Angle position calculationAngle position calculation

Orbit determinationOrbit determination

delay delay rate

R.A. Dec.

VLBI centerVLBI center

Chang’E satellite tracking as lunar mission succeeded

Lunar map obtained by Chang’E

FAST FAST (Five hundred meter Aperture Spherical radio Telescope)(Five hundred meter Aperture Spherical radio Telescope)

Korea-Japan Collaboration for new corKorea-Japan Collaboration for new correlator and data center developmentrelator and data center development

2005-20092005-2009• KASI and NAOJ signed MOU for developmentKASI and NAOJ signed MOU for development

Correlator at SeoulCorrelator at Seoul 8Gbps x 16 stations8Gbps x 16 stations UsageUsage

• KVNKVN• East Asia VLBI networkEast Asia VLBI network• VSOP-2VSOP-2

ＶＥＲＡ

terminal

Korea/China

(Mark-V)

Japan Univ. (K-5)

Optical fiber

(VSI-E)

ＶＬＢＩ data server

Wideband correlator

8Gbps

16 stations Data processing and archive

Operation System

New Correlator at Seoul -Joint development with Korea and Japan –

Software correlator

1Gbpsx4 stations

VSOP-2VSOP-2

Talk of Doi-san

AGN accretion disk imagingAGN accretion disk imaging

AGN jet uniform schemeAGN jet uniform scheme

ConclusionConclusion

East Asia VLBI network has large possibilitEast Asia VLBI network has large possibilityy• 100 mas 100 mas ～　～　 1010 　　 μas (including VSOP-2)μas (including VSOP-2)• Around 20 stations are possible.Around 20 stations are possible.• CVN, KVN, JVN are started individually.CVN, KVN, JVN are started individually.• EAVN test observations have been started.EAVN test observations have been started.

Need actual organization scheme of observNeed actual organization scheme of observations and sciencesations and sciences