about JVN about JVN Status Status Results Results Future plans Future plans Japanese VLBI Network (JVN): recent results and future plans for EAVN Kenta Fujisawa (Yamaguchi University) 2009 East Asia VLBI Workshop Seoul 09/03/18-20 Telescopes of JVN

Japanese VLBI Network (JVN) Collaboration Collaboration NAOJ (VERA) NAOJ (VERA) Hokkaido, Ibaraki, Tsukuba, Gifu, Osaka-Pref, Yamaguchi, Kagoshima university Hokkaido, Ibaraki, Tsukuba, Gifu, Osaka-Pref, Yamaguchi, Kagoshima university JAXA, NICT, GSI JAXA, NICT, GSI 13 telescopes (11m ~ 64m) 13 telescopes (11m ~ 64m) Purpose Purpose A new, characteristic VLBI array A new, characteristic VLBI array Ground Array for VSOP-2 Ground Array for VSOP-2 A Base of East-Asian VLBI A Base of East-Asian VLBI Progress Progress Started in 2004 Started in 2004 Steady Observation in 2005 Steady Observation in 2005 First Paper published in 2006 First Paper published in 2006 Observing time ~200 hr/yr Observing time ~200 hr/yr EAVN test observation EAVN test observation JVN 13 Telescopes

JVN array Baseline 2500 km Baseline 2500 km Frequency Bands 8/22/6.7 GHz Frequency Bands 8/22/6.7 GHz 8 – continuum, 22 – water maser/cont, 6.7 – methanol 8 – continuum, 22 – water maser/cont, 6.7 – methanol Beam size Beam size GHz GHz 3 8 GHz 3 8 GHz 1 22 GHz 1 22 GHz Sensitivities (8 GHz) Sensitivities (8 GHz) Detection3 mJy with Phase-Referencing Detection3 mJy with Phase-Referencing Image brightness10 6 K Image brightness10 6 K New Technologies New Technologies High-Speed e-VLBI (2 Gbps) in a subarray High-Speed e-VLBI (2 Gbps) in a subarray JVN is an established VLBI network now

Publications of JVN in The 2006 Radio Outbursts of a Microquasar Cygnus X-3: Observations and Data Tsuboi et al. (2008), PASJ, 60, 465 Tsuboi et al. (2008), PASJ, 60, A Synchronized Variation of the 6.7 GHz Methanol Maser in Cepheus A Sugiyama et al.(2008), PASJ, 60, 1001 Sugiyama et al.(2008), PASJ, 60, Mapping Observations of 6.7 GHz Methanol Masers with the Japanese VLBI Network Sugiyama et al. (2008), PASJ, 60, 23 Sugiyama et al. (2008), PASJ, 60, Microstructure and kinematics of H2O masers in the massive star forming region IRAS Motogi et al. (2008), MNRAS, 390, 523 Motogi et al. (2008), MNRAS, 390, H 2 O Maser Outflow from the Red Supergiant Star NML Cygni observed with Japanese VLBI Network Nagayama et al. (2008), PASJ, 60, 1069 Nagayama et al. (2008), PASJ, 60, 1069

8 GHz Observation Narrow-Line Seyfert 1 Radio Galaxy Doi et al. (2007) Observation Observation 8.4 GHz, Phase- referencing 8.4 GHz, Phase- referencing 5 sources 5 sources Results Results Tb ~ 10 7 K Tb ~ 10 7 K → Synchrotron radiation, but inverted spectrum → Synchrotron radiation, but inverted spectrum Doppler boosting is significant for the radio property of NLS1 Doppler boosting is significant for the radio property of NLS1

Flare of Micro-quasar Cyg X-3 Tsuboi et al. (2008) Observation Observation 2006 Feb flare 2006 Feb flare Only 3.5 days after a major flare Only 3.5 days after a major flare Results Results Simple circular structure Simple circular structure Low-noise map Low-noise map  Tb = 1.4 x 10 6 K  Tb = 1.4 x 10 6 K No jet is seen No jet is seen Jet is formed >3.5 days after a flare Jet is formed >3.5 days after a flare

22GHz Observation Late-type star NML-Cyg Late-type star NML-Cyg Nagayama et al. (2008) PASJ Nagayama et al. (2008) PASJ Led by Kagoshima Univ Led by Kagoshima Univ Star forming region WB755 Star forming region WB755 Motogi et al. (2008) MNRAS Led by Hokkaido Univ

6.7 GHz Methanol Maser Cep A (Sugiyama et al. 2008) W3(OH) to be published

Future Plan of JVN New VLBI system New VLBI system 1/2 Gbps back-end system to be installed (delayed…) 1/2 Gbps back-end system to be installed (delayed…) Mitaka Software correlator / Seoul correlator Mitaka Software correlator / Seoul correlator East-Asian VLBI Network (EAVN) East-Asian VLBI Network (EAVN) Collaboration with CVN/KVN (and Australia) Collaboration with CVN/KVN (and Australia) Seoul – Mizusawa (Nov 2008) fringe detection ! Seoul – Mizusawa (Nov 2008) fringe detection ! China – Japan experiment started in Feb 2009 (Miyazaki-san) China – Japan experiment started in Feb 2009 (Miyazaki-san) Imaging test -> scientific observation in 2009 Imaging test -> scientific observation in 2009 VSOP-2 (2012~) VSOP-2 (2012~) JVN / EAVN to be one of the Ground VLBI Arrays JVN / EAVN to be one of the Ground VLBI Arrays Preparation for VSOP-2 Preparation for VSOP-2

2500 km 5000 km East-Asian VLBI Network (EAVN)

uv coverage 8000 x 5000 km 0.3 x 0.5 mas 1σ = 50 μJy/beam = 10^7.2 K (1hr) 1σ = 150 μJy/beam = 10^7.2 K (1hr) 1σ = 200 μJy/beam = 10^7.6 K (1hr) 9000 x 5000 km 0.3 x 0.5 mas 5000 x 4000 km 0.5 x 0.6 mas EAVN 22 GHzEVN 22 GHz VLBA 22 GHz (Simulation : A. Doi)

EAVN Scientific observations in 2009 A plan of the scientific observations in 2009 A plan of the scientific observations in 2009 NowFringe detection experiments NowFringe detection experiments Apr – JunImaging experiments (8/22GHz) Apr – JunImaging experiments (8/22GHz) Jul -Scientific observations Jul -Scientific observations DecFirst result (next East Asia VLBI WS) DecFirst result (next East Asia VLBI WS) Science (just my rough idea) Science (just my rough idea) Monitoring of 3C84 of starting outburst (8/22 GHz) Monitoring of 3C84 of starting outburst (8/22 GHz) Monitoring of internal motion of H 2 O maser source Monitoring of internal motion of H 2 O maser source Monitoring / intensive observation of micro-quasars Monitoring / intensive observation of micro-quasars Imaging survey of new kind of AGNs (such as BAL) Imaging survey of new kind of AGNs (such as BAL) … Who ? How ? >> ‘Core group’ Who ? How ? >> ‘Core group’

Thank you !