Next Space VLBI mission: VSOP-2
Y.Murata (ISAS/JAXA)
Next Generation Space VLBI WGH.Hirabayashi, M.Natori, P.G.Edwards, Y.Asaki, N.Mochizuki, T.Toda, … (ISAS/JAXA),
M.Inoue, S.Kameno, M.Tsuboi, Y.Kono, K.Asada, A.Doi, H.Nagai, H.Kobayashi, K.Bushimata, N.Kawaguchi, S.Iguchi, … (NAOJ)
T.Kondo, Y.Koyama (NICT)
K.Fujisawa (Univ. of Yamaguchi),
T.Omodaka(Univ.of Kagoshima),
H.Sudo (Univ. of Gifu), K.Wajima (KVN)
T.Kasuga (Hosei Univ.), S.Sawada-Sato (ASIAA)
International collaboratorsJPL, NRAO, ATNF, DRAO, JIVE/EVN, China, ..
VSOP
HALCA and VSOPHighly Advanced Laboratory for Communications and Astronomy
VLBI Space Observatory Programme
1.6 GHz (18 cm)5 GHz (6 cm)x[ 22 GHz (1.3cm)]
34,000 km
Launch: Feb. 1997ISAS M-V rocket
Resolution of360 μarcseconds at λ= 6 cm
Lobanov, A.P. 2003, SKA Memo 38
VSOP
Presentstatus
Resolution of current & future telescopes in all wavelength
Plasma torus
VSOP observation results
• FIRST Space VLBI Mission
• Physics of the Active Galactic Nuclear (AGN)– Structure and motion of the
AGN jets
– Torus around the AGN core
– Extremely high brightness temperature objects
(TB=1014 K)
Beamwidth 100 Rs at 5 GHz for M87
Plasma Torus in absorption5-years jet monitor of 1928+738
Jet Structure
VSOP publications
Advances
In Space
Research VSOP symposium
PASJ VSOP issue
Success of large scaleInternational Collaboration
HALCA Tracking Stations: NASA DSN (Goldstone, Tidbinbilla, Madrid), NRAO Green Bank, Usuda (ISAS)Navigation: NASA JPL, ISASCorrelators VLBA (NRAO), Penticton (DRAO, Canada), Mitaka (NAOJ) Radio Telescopes: VLBA, VLA, Green Bank 140 ft (NRAO), Arecibo, DSN 70m (GO, TI, RO), Jodrell Bank, Westerbork, Onsala, Effelsberg, Torun, Noto, Metsahovi, Kalyazin, Shanghai, Hartebeesthoek, ATCA, Hobart, Ceduna, Mopra, Usuda, Kashima (14 countries, 32 telescopes)
VSOP-2
VSOP-2 is the upgraded space VLBI mission following the VS
OP mission.
10 times higher sensitivity.
10 times higher frequency
observation
10 times higher resolution with ~ 40 μarcseconds (43 GHz).
Observing band 8, 22, 43 GHz (Wavelength of 3.8, 1.3 and 0.7 cm)
Dual polarization
Phase-referencing capability
VSOP-2 Mission
Lobanov, A.P. 2003, SKA Memo 38
VSOP-2
Resolution of current & future telescopes in all wavelength
VSOP
Presentstatus
Characteristics of the future radio telescopes
Sensitivity
ResolutionHigherFrequency
SKA(Square Kilometer Array)
ALMA
VSOP-2
Launcher and orbit• Launcher : M-V rocket by JAXA
• Orbit : (cf HALCA)
– Apogee 25,000 km (21,300 km) Perigee 1,000 km (560 km)
– inclination 31° (31 °)
– period 7.5 hour (6.3 hour)
• Mass 910 kg (831 kg)
• Power 1,800 W (700 W)
• Launch : 2011 in earliest caes
VSOP-2 Science Targets
• Key science :– Jet structure, collimation and acceleration – Structure of plasma tori, accretion disks, BHs in acti
ve galactic nucleus (AGN)– Structure of magnetosphere in protostars
• Other science targets:– Galactic masers in star-forming region– Extragalactic Megamasers– Radio quiet quasars– X-ray binaries, SNR, gravitational lenses etc.
a-c: inclination 20°
g-I: inclination 45°
Look at the BLACK HOLE !?
Schwartschild………………...…..Extreme Kerr
Model
VSOP-2 image
Model
VSOP-2 image
Imaging of Accretion Disk ADAF 、 TB=109-10 K ( Standard Disk = 105K )
Black Hole 10 Rg resolution @ M87 distance
(Takahashi et al. 2004)
Magneto-HydroDynamic Simulation (Meier et al. 2001)
Rotating accretion disk + Magnetic Fiels
Polarization Image byVSOP
VSOP-2 enables full-polarization Image
Dynamics of galaxies and the star forming regions using maser emission
• Mega-maser in NGC4258 type galaxies– Measurement of the proper
motion in short timescale
– Doppler shift measurement
– 3 dimensional dynamics
– Estimation of the central mass
• Star Forming Region• Late Type Stars
NGC4258 Miyoshi et al. 1995
VSOP-2 satellite• 9-m offset Cassegrain antenna with modular
structure– Light weight
VSOP-2 engineering developments
•Large deployable antenna for λ=7 mm •High data rate sampling of the data•1 Gbps data transmission•Cooled low noise amplifiers on board.•Development of the phase-referencing
Switching capability•Total satellite system design
Mass budgetPower budgetHeat control systemAttitude control systemPower supply systemStructure fit to the M-V fairing
Deployment mechanism of theModular antenna structure
• Same deployment mechanism as ETSVIII – modular antenna
structure
Launch 2006 ?
ETS-VIII(JAXA)
Deployment image of ETS-VIII
Deployment test of ETS-VIII
Development of a high accuracy antenna module
⑥
②
③
④ ⑤
⑦
構体中心軸
サポートブーム
①
対称鏡面
※ 放射面側から見る
Ya
Xa
設計対象 鏡面
Deployment system test.
Confirmed mechanical structure
Deployment of the module
Radiation test of the high speed A/D LSI
Total dose test (April 2001)Single event test ( August 2001)
10 Gbps 1 bit A/D1:16 DEMUX
Correlator
Heavy ion beam
• 4 reaction wheels and 2 CMG for rapid switching
•CMG•changes the direction of the spin axis set by the reaction wheels
•Simulations•Assuming :
•Switching cycle 1 minute•Amplitude 3.5 °•Flexible structure body
Attitude error < 0.005°
separation angle < 3°
Switching cycle < 1min.
CMG control test
Solution of high torque actuator
International Collaborations
• International collaboration based on VSOP experience– Correlators, tracking stations, orbit determination
– Ground telescopes commitments based on GVWG (Global VLBI Working Group) discussion.
• Many new Ground Telescopes • VERA 4 stations, Yamaguchi, Uchinoura ,
• KVN 3 stations,
• Urumqi, Delingha, Beijing
• Sardinia, Yebes
• GBT
– Possibility of SKA with VSOP-2
Status of VSOP-2
• JAXA/ISAS– Developments are going.– The VSOP-2 mission proposal was
submitted to ISAS Science Steering Committee in October, 2003, but could not go to the budget request.
– Revised version of the proposal will be submitted soon as an M-V mission @ 2011
– 3 missions are the candidates to be approved.
• NAOJ– Space VLBI project office for VSOP-2 is started from last April– NAOJ and ISAS will be core institute for the VSOP-2 mission, as we
did in the VSOP mission.