Japanese VLBI Network (JVN): recent results and future plans for EAVN

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

2. Japanese VLBI Network (JVN) • Collaboration • NAOJ (VERA) • Hokkaido, Ibaraki, Tsukuba, Gifu, Osaka-Pref, Yamaguchi, Kagoshima university • JAXA, NICT, GSI • 13 telescopes (11m ~ 64m) • Purpose • A new, characteristic VLBI array • Ground Array for VSOP-2 • A Base of East-Asian VLBI • Progress • Started in 2004 • Steady Observation in 2005 • First Paper published in 2006 • Observing time ~200 hr/yr • EAVN test observation 2008- JVN 13 Telescopes

3. JVN array • Baseline 2500 km • Frequency Bands 8/22/6.7 GHz • 8 – continuum, 22 – water maser/cont, 6.7 – methanol • Beam size • 5 mas @ 6.7 GHz • 3 mas @ 8 GHz • 1 mas @ 22 GHz • Sensitivities (8 GHz) • Detection 3 mJy with Phase-Referencing • Image brightness 106 K • New Technologies • High-Speed e-VLBI (2 Gbps) in a subarray JVN is an established VLBI network now

4. Publications of JVN in 2008 • The 2006 Radio Outbursts of a Microquasar Cygnus X-3: Observations and Data • Tsuboi et al. (2008), PASJ, 60, 465 • A Synchronized Variation of the 6.7 GHz Methanol Maser in Cepheus A • Sugiyama et al.(2008), PASJ, 60, 1001 • Mapping Observations of 6.7 GHz Methanol Masers with the Japanese VLBI Network • Sugiyama et al. (2008), PASJ, 60, 23 • Microstructure and kinematics of H2O masers in the massive star forming region IRAS 06061+2151 • Motogi et al. (2008), MNRAS, 390, 523 • H2O Maser Outflow from the Red Supergiant Star NML Cygni observed with Japanese VLBI Network • Nagayama et al. (2008), PASJ, 60, 1069

5. 8 GHz ObservationNarrow-Line Seyfert 1 Radio GalaxyDoi et al. (2007) • Observation • 8.4 GHz, Phase-referencing • 5 sources • Results • Tb ~ 107K • → Synchrotron radiation, but inverted spectrum • Doppler boosting is significant for the radio property of NLS1

6. Flare of Micro-quasar Cyg X-3Tsuboi et al. (2008) • Observation • 2006 Feb flare • Only 3.5 days after a major flare • Results • Simple circular structure • Low-noise map • DTb = 1.4 x 106 K • No jet is seen • Jet is formed >3.5 days after a flare

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

8. 6.7 GHz Methanol Maser Cep A (Sugiyama et al. 2008) W3(OH) to be published

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

10. 2500 km 5000 km East-Asian VLBI Network (EAVN)

11. uv coverage EVN 22 GHz EAVN 22 GHz VLBA 22 GHz 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 8000 x 5000 km 0.3 x 0.5 mas (Simulation : A. Doi)

12. EAVN Scientific observations in 2009 • A plan of the scientific observations in 2009 • Now Fringe detection experiments • Apr – Jun Imaging experiments (8/22GHz) • Jul - Scientific observations • Dec First result (next East Asia VLBI WS) • Science (just my rough idea) • Monitoring of 3C84 of starting outburst (8/22 GHz) • Monitoring of internal motion of H2O maser source • Monitoring / intensive observation of micro-quasars • Imaging survey of new kind of AGNs (such as BAL) • … • Who ? How ? >> ‘Core group’

13. Thank you !