Status and future of East Asia VLBI network H.Kobayashi(NAOJ) East Asia VLBI

Current working VLBI stations Japan(13) Japan(13) VERA(4), Kashima, Tsukuba, Yamaguchi, Nobeyama, Usuda, Tomakomai, Gifu, Uchinoura, Takahagi, HitachiVERA(4), Kashima, Tsukuba, Yamaguchi, Nobeyama, Usuda, Tomakomai, Gifu, Uchinoura, Takahagi, Hitachi Korea(3) Korea(3) KVN (3) Seoul, Ulsan, JejuKVN (3) Seoul, 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 network Largest number of VLBI stations Largest number of VLBI stations 8GHz 13 stations8GHz 13 stations 22GHz 19 stations22GHz 19 stations 43GHz 8 stations43GHz 8 stations Phase referencing Phase referencing VERA 2 beam systemVERA 2 beam system KVN multi-frequency + fast noddingKVN multi-frequency + fast nodding Good UV coverage Good UV coverage Minimum baseline length ; 50 kmMinimum baseline length ; 50 km Maximum baseline length ; 6000 kmMaximum baseline length ; 6000 km

Scientific objectives of EAVN Astrometry and phase referencing VLBI Astrometry and phase referencing VLBI VERA + KVN : 20m x GHzVERA + KVN : 20m x GHz JVN + CVN : methanol maser + CVN : methanol maser Sensitive imaging 8/22 GHz Sensitive imaging 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 network Joint 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 network Including VERA Korean VLBI network Chinese VLBI network

Assumption of Observation Time (2010~) EAVN 2,000 H/Y 2,500 1,500 1,000 Geodesy 1,000 KVN 5,000 H/Y VERA 5,000 H/Y Seoul 6,000 H/Y Mitaka 2,500 H/Y VSOP-2

Science (Dec. 5,2008)

Results of VERA measurements Sun S269 Milky way galaxy Illustration courtesy: NASA/JPL-Caltech/R. Hurt (SSC/Caltech) NGC 281 ρ oph S Crt Orion NGC 1333 Sun neighborhood VY CMa Parallax + Proper motion Proper motion Sgr A OH43 W49N ON2

Kaguya (RISE) mission Precise gravity field of moon -> cooling time differences between farside and nearside

Takahagi/Hitachi; New VLBI station Takahagi/ Hitachi Kashima Tsukuba Usuda １００ ｋｍ ５０ｋ ｍ ２００ ｋｍ 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 !

First fringe between Seoul and

1993 (25m) 1987 (25m) 2006 (40m) 2006 (50m) Chinese VLBI Network 2006

Correlator 4 station software VLBI correlator 4 station software VLBI correlator 5 stations hardware VLBI correlator 5 stations hardware VLBI correlator (128MHz bandwidth) (128MHz bandwidth) e-VLBI (16Mbiteps) for 4 stations in 10 minutes e-VLBI (16Mbiteps) for 4 stations in 10 minutes

VLBI Correlator Data reduction Angle position calculation Orbit determination delaydelay rate R.A.Dec. VLBI center Chang ’ E satellite tracking as lunar mission succeeded Lunar map obtained by Chang ’ E

FAST (Five hundred meter Aperture Spherical radio Telescope)

Korea-Japan Collaboration for new correlator and data center development KASI and NAOJ signed MOU for development KASI and NAOJ signed MOU for development Correlator at Seoul Correlator at Seoul 8Gbps x 16 stations 8Gbps x 16 stations Usage Usage 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) ＶＬＢ Ｉ 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-2 Talk of Doi-san

AGN accretion disk imaging

AGN jet uniform scheme

Conclusion East Asia VLBI network has large possibility East Asia VLBI network has large possibility 100 mas ～ 10 μas (including VSOP- 2)100 mas ～ 10 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 observations and sciences Need actual organization scheme of observations and sciences