Next Space VLBI mission: VSOP-2 Y.Murata (ISAS/JAXA) Next Generation Space VLBI WG H.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 collaborators JPL, NRAO, ATNF, DRAO, JIVE/EVN, China, .. I’m a member of VSOP group in ISAS Japan. Today, I talk about a next generation space-VLBI mission, we call VSOP-2.

VSOP

34,000 km HALCA and VSOP 1.6 GHz (18 cm) 5 GHz (6 cm) VLBI Space Observatory Programme HALCA and VSOP Highly Advanced Laboratory for Communications and Astronomy 1.6 GHz (18 cm) 5 GHz (6 cm) x[ 22 GHz (1.3cm)] 34,000 km Launch: Feb. 1997 ISAS M-V rocket Resolution of 360 μarcseconds 　 at λ= 6 cm

Resolution of current & future telescopes in all wavelength Present status ＶＳＯＰ Lobanov, A.P. 2003, SKA Memo 38

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 Jet Structure Plasma torus Plasma Torus in absorption ISAS and international partners have succeeded VSOP which is the first VLBI imaging mission. So, we could studies about AGN jet environment and jet physics: As you know…. Structure … Time variation of jet in high resolution. And HALCA is still living, NGC4261 parsec-scale structure by free-free absorption Jones et al. (2000) 1928+738 4 year monitering observation. Murphy AGNのジェットと核周物質の物理の解明 活動銀河核からのジェットの構造、運動 吸収による銀河中心部のトーラス構造の解明 高輝度温度天体の存在を示す。 5-years jet monitor of 1928+738

VSOP publications PASJ VSOP issue Advances In Space Research VSOP symposium

Success of large scale International Collaboration HALCA Tracking Stations: NASA DSN (Goldstone, Tidbinbilla, Madrid), NRAO Green Bank, Usuda (ISAS) Navigation: NASA JPL, ISAS Correlators 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

Phase-referencing capability VSOP-2 Mission VSOP-2 is the upgraded space VLBI mission following the VSOP 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

Resolution of current & future telescopes in all wavelength Present status ＶＳＯＰ ＶＳＯＰ－２ Lobanov, A.P. 2003, SKA Memo 38

Characteristics of the future radio telescopes Sensitivity SKA (Square Kilometer Array) ALMA Higher Frequency Resolution 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 For the launcher, we are assuming the rocket to be M-V. The possibility of launching satellite with HII still remains, too. If so, we can get additional mass budget, fairing space and apogee height. But for now, M-V is more realistic.

VSOP-2 Science Targets Key science : Jet structure, collimation and acceleration Structure of plasma tori, accretion disks, BHs in active 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. Following these success of VSOP, science targets of VSOP-2 approach the central region of AGN. studies of accretion disks and jets in AGN studies of non-thermal emission from YSOs And we revenge the maser observations. the highest resolution studies of Galactic masers and extragalactic megamasers. And the capability of other observations have been discussing.

Look at the BLACK HOLE !? (Takahashi et al. 2004) a-c: inclination 20° 　　　20° g-I: inclination 　　　45° 　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) Schwartschild………………...…..Extreme Kerr

Magneto-HydroDynamic Simulation (Meier et al. 2001) Rotating accretion disk + Magnetic Fiels Polarization Image by VSOP 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 budget Power budget Heat control system Attitude control system Power supply system Structure fit to the M-V fairing Observing frequencies of VSOP-2 are these. We revenge the 22GHz of HALCA. For now, 22 and 43 GHz receivers are cooled. But 8GHz is not cooled because of the restriction of mass and power budget. Wide band data downlink is one of technical challenges. These bring the improvement of sensitivity. Apogee height is about 25000km, so we can get the resolution of 75 mas for 22GHz and… And other option are these. Phase-ref brings more higher sensitivity and astrometric observation. Dual polarization bring us the studies of magnetic field.

Deployment mechanism of the Modular antenna structure Launch 2006 ? ETS-VIII(JAXA) Same deployment mechanism as ETSVIII modular antenna structure Deployment image of ETS-VIII We use … NASDA HPでcheck! Deployment test of ETS-VIII

Development of a high accuracy antenna module 図中を英語に Antenna surface of ETS-VIII is cable **** We need a surface accuracy of 0.4mm for 43GHz observation. Now, may be this or next week, mesh will be stretched on the surface

Deployment of the module Deployment system test. Confirmed mechanical structure

Radiation test of the high speed A/D LSI Total dose test (April 2001) Single event test （August 2001) 1:16 DEMUX 10 Gbps 1 bit A/D Heavy ion beam Correlator

Solution of high torque actuator 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 CMG control test separation angle < 3° will allow rapid switching for phase referencing Switching cycle < 1min. Attitude error < 0.005°

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.