about JVNabout JVN StatusStatus ResultsResults Future plansFuture plans

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

Kenta Fujisawa(Yamaguchi University)

2009 East Asia VLBI WorkshopSeoul 09/03/18-20

Telescopes of JVN

Japanese VLBI Network (JVN)Japanese VLBI Network (JVN) CollaborationCollaboration

NAOJ (VERA)NAOJ (VERA) Hokkaido, Ibaraki, Tsukuba, GiHokkaido, Ibaraki, Tsukuba, Gi

fu, Osaka-Pref, Yamaguchi, Kfu, Osaka-Pref, Yamaguchi, Kagoshima universityagoshima university

JAXA, NICT, GSIJAXA, NICT, GSI 13 telescopes (11m ~ 64m)13 telescopes (11m ~ 64m)

PurposePurpose A new, characteristic VLBI arraA new, characteristic VLBI arra

yy Ground Array for VSOP-2Ground Array for VSOP-2 A Base of East-Asian VLBIA Base of East-Asian VLBI

ProgressProgress Started in 2004Started in 2004 Steady Observation in 2005Steady Observation in 2005 First Paper published in 2006First Paper published in 2006

Observing time ~200 hr/yrObserving time ~200 hr/yr EAVN test observation 2008-EAVN test observation 2008-

JVN 13 Telescopes

JVN arrayJVN array Baseline 2500 kmBaseline 2500 km Frequency Bands 8/22/6.7 GHzFrequency Bands 8/22/6.7 GHz

8 – continuum, 22 – water maser/cont, 6.7 – methanol8 – continuum, 22 – water maser/cont, 6.7 – methanol Beam sizeBeam size

5 mas @ 6.7 GHz5 mas @ 6.7 GHz 3 mas @ 8 GHz3 mas @ 8 GHz 1 mas @ 22 GHz1 mas @ 22 GHz

Sensitivities (8 GHz)Sensitivities (8 GHz) DetectionDetection 3 mJy with Phase-Referencing3 mJy with Phase-Referencing Image brightnessImage brightness 101066 K K

New TechnologiesNew Technologies High-Speed e-VLBI (2 Gbps) in a subarrayHigh-Speed e-VLBI (2 Gbps) in a subarray

JVN is an established VLBI network now

Publications of JVN in 2008Publications of JVN in 2008

1.1. The 2006 Radio Outbursts of a Microquasar Cygnus X-3: ObservatiThe 2006 Radio Outbursts of a Microquasar Cygnus X-3: Observations and Dataons and Data

• Tsuboi et al. (2008), PASJ, 60, 465Tsuboi et al. (2008), PASJ, 60, 465

2.2. A Synchronized Variation of the 6.7 GHz Methanol Maser in CepheuA Synchronized Variation of the 6.7 GHz Methanol Maser in Cepheus As A

• Sugiyama et al.(2008), PASJ, 60, 1001Sugiyama et al.(2008), PASJ, 60, 1001

3.3. Mapping Observations of 6.7 GHz Methanol Masers with the JapanMapping Observations of 6.7 GHz Methanol Masers with the Japanese VLBI Networkese VLBI Network

• Sugiyama et al. (2008), PASJ, 60, 23Sugiyama et al. (2008), PASJ, 60, 23

4.4. Microstructure and kinematics of H2O masers in the massive star foMicrostructure and kinematics of H2O masers in the massive star forming region IRAS 06061+2151rming region IRAS 06061+2151

• Motogi et al. (2008), MNRAS, 390, 523Motogi et al. (2008), MNRAS, 390, 523

5.5. HH22O Maser Outflow from the Red Supergiant Star NML Cygni obserO Maser Outflow from the Red Supergiant Star NML Cygni obser

ved with Japanese VLBI Networkved with Japanese VLBI Network• Nagayama et al. (2008), PASJ, 60, 1069Nagayama et al. (2008), PASJ, 60, 1069

8 GHz Observation8 GHz ObservationNarrow-Line Seyfert 1 Radio GalaxyNarrow-Line Seyfert 1 Radio Galaxy

Doi et al. (2007)Doi et al. (2007)

ObservationObservation 8.4 GHz, Phase-8.4 GHz, Phase-

referencingreferencing 5 sources5 sources

ResultsResults Tb ~ 10Tb ~ 1077KK → → Synchrotron radiation, Synchrotron radiation,

but inverted spectrumbut inverted spectrum

Doppler boosting is Doppler boosting is significant for the radio significant for the radio property of NLS1property of NLS1

Flare of Micro-quasar Cyg X-3Flare of Micro-quasar Cyg X-3Tsuboi et al. (2008)Tsuboi et al. (2008)

ObservationObservation 2006 Feb flare2006 Feb flare Only 3.5 days after a majOnly 3.5 days after a maj

or flareor flare

ResultsResults Simple circular structureSimple circular structure

Low-noise mapLow-noise map Tb = 1.4 x 10Tb = 1.4 x 1066 K K

No jet is seenNo jet is seen Jet is formed >3.5 days aftJet is formed >3.5 days aft

er a flareer a flare

22GHz Observation22GHz Observation Late-type star NML-CygLate-type star NML-Cyg

Nagayama et al. (2008) PASJNagayama et al. (2008) PASJ Led by Kagoshima UnivLed by Kagoshima Univ

Star forming region WB755Star forming region WB755 Motogi et al. (2008) MNRASMotogi et al. (2008) MNRAS Led by Hokkaido UnivLed by Hokkaido Univ

6.7 GHz Methanol Maser6.7 GHz Methanol Maser

Cep A(Sugiyama et al. 2008)

W3(OH)to be published

Future Plan of JVNFuture Plan of JVN New VLBI systemNew 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 correlatorMitaka 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 2009Imaging test -> scientific observation in 2009

VSOP-2 (2012~)VSOP-2 (2012~) JVN / EAVN to be one of the Ground VLBI ArraysJVN / EAVN to be one of the Ground VLBI Arrays Preparation for VSOP-2Preparation for VSOP-2

2500

km

5000 km

East-Asian VLBI Network (EAVN)

uvuv coverage coverage

8000 x 5000 km0.3 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 km0.3 x 0.5 mas

5000 x 4000 km0.5 x 0.6 mas

EAVN 22 GHzEVN 22 GHz VLBA 22 GHz

(Simulation : A. Doi)

EAVN Scientific observations in 2009EAVN Scientific observations in 2009

A plan of the scientific observations in 2009A plan of the scientific observations in 2009 NowNow Fringe detection experimentsFringe detection experiments Apr – JunApr – Jun Imaging experiments (8/22GHz)Imaging experiments (8/22GHz) Jul -Jul - Scientific observationsScientific observations DecDec First result (next East Asia VLBI WS)First 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 HMonitoring of internal motion of H22O maser sourceO maser source Monitoring / intensive observation of micro-quasarsMonitoring / 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 !Thank you !