Astro -G, KVN/VERA(EAVN), VLBA, ALMA の現状と今後
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Transcript of Astro -G, KVN/VERA(EAVN), VLBA, ALMA の現状と今後
Astro-G, KVN/VERA(EAVN), VLBA, ALMA の現状と今後
H.Kobayashi(NAOJ)2011, Sep.,27
多波長で探る AGN ジェット研究会
Target Life Time is 3 years.
Dual pol. @ 8, 22, 43 GHz Phase-referencing capability Switching Maneuver 10 cm Orbit Determination
9.3 m Antenna with high surface accuracy (0.4mm rms)precision pointing (0.005deg)
1 Gbps Data Downlink
ASTRO-G Mission
Cancellation of Astro-G
2009.3-7 PDR• Uncertainty of deployment antenna repeatability• Problems of surface accuracy (thermal conditions,
radiation conditions) 2009.7-2010.8 Tiger team activity
• Only 1mm rms is achievable.• Cost will overrun more than 50% of initial cost.
2010.9 ISAS Science council recommended the cancellation.
2010.12 ISAS advisory council also recommended it. 2011.09 宇宙開発委員会での結論
East Asian VLBI Network array
Current working VLBI stations in Eastern Asia
Japan(13)• VERA(4), Kashima, Tsukuba, Yamaguchi,
Nobeyama, Usuda, Tomakomai, Gifu, Uchinoura, Takahagi, Hitachi
Korea(3)• KVN (3) Yonsei, Ulsan, Tamna
China(4)• Shanghai, Urumqi, Beijin, Kumming• Shanghai 65m
Feature of East Asia VLBI network
Largest number of VLBI stations• 8GHz 13 stations• 22GHz 19 stations• 43GHz 8 stations• S/X geodesy 13 stations
Phase referencing• VERA 2 beam system• KVN multi-frequency + fast nodding
Good UV coverage• Minimum baseline length ; 50 km• Maximum baseline length ; 5000 km
Observation features
Phase referencing observations• VERA 2 beam• KVN multi-frequency• Nodding -> high sensitivity observations for low Tb objects
(RQQ, SNR, Galactic objects) ->astrometry for maser sources (H2O,SiO,CH3OH..)
High dynamic range observations
Ground array of VSOP-2
Total effective aperture and baseline length
VLBI array EAVN VLBA EVN
No. of Stations
20 10 12
Baseline length
5,000km 8,000km 2,000km-8,000km
Effective Aperture 8GH z
9,000m2 3,700m2 9,800m2
Effective Aperture 22GHz
4,900m2 3,200m2 4,900m2
Effective Aperture 43GHz
1,400m2 2,900m2 1,800m2
Current status of astrometry with VERA
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• 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
Simultaneous Multi-Frequency Obs. -Phase Compensation, mm-VLBI
Constructions of three stations were completed on Dec. 2008 !
Freq. Band S Band X Band K Band Q Band
Freq. Range 2.2 ~ 2.8 GHz 8 ~ 9 GHz 21.5 ~23.5 GHz 42 ~ 44 GHz
Rx Noise < 25 K < 25 K < 30 K < 50 K
1st IF / BW 2.5G/600MHz 8.5G/1GHz 8.5G/2GHz 8.5G/2GHz
IF Power -20 dBm -20 dBm -20 dBm -20 dBm
Polarization LCP/RCP LCP/RCP LCP/RCP LCP/RCP
* 86, 129 GHz Receivers will be installed.
Prototype 43 GHz Re-ceiver
Receiver
Seoul VLBI correlator center
Opened on May 13th, 2010
8Gbps x 16 station Largest VLBI correlator
VERA/Tape
terminal
Korea/China
(Mark-5b)
VERA/Disk
(VOA)
Optical fiber
(VSI-E)
VLBI data server
Wideband correlator
8Gbps
16 stations Data processing and archive
Operation System
New Correlator at Seoul - Joint development with Korea and Japan –
Software correlator
1Gbpsx4 stations
Schedule
2010 • Test Observations with VERA+KVN
2011• Start of science observations with Japan
(VERA,JVN) /Korea (KVN), and Japan(JVN)/China(CVN).
2012• Start of science observations with Japan,
Korea and China
Atacama Large Millimeter/submillimeter ArrayExpanded Very Large Array
Robert C. Byrd Green Bank TelescopeVery Long Baseline Array
VLBA Operational StatusOngoing and Possible Future Upgrades
Walter BriskenNRAO, Socorro
Current capabilities of the VLBA 45 baselines from 10 identical 25m antennas Peak / sustainable record rate is 512 Mbps
• 64 MHz/polarization with 2-bit samples Operates at select bands between 330 MHz and
90 GHz• Dual band 2.2 / 8.4 GHz supported
1-hour continuum sensitivity at 8.4 GHz = 54 Jy RMS
Angular resolution at 8.4 GHz is 1x2 mas
18
Current capabilities of the VLBA
Absolute astrometry to a precision of 100 as Relative astrometry to a precision of 10 as Flexible correlation with DiFX
• Can correlate at ~700 Mbps x 10 antennas for typical projects
• 16 playback Mark5 units available• Transient processor
VLBA Sensitivity Upgrade Project(http://www.vlba.nrao.edu/memos/sensi/)
Began as a project in 2007 Three major components of the upgrade are:
• New correlator DiFX software correlator was ultimately chosen
• New data recorder Mark5C, developed by Haystack/Conduant/NRAO
• New antenna back-end electronics ROACH FPGA-based Digital Back End (RDBE) in
development Project funded (including media) to complete 2 Gbps
capability• Funding from NRAO, NSF MRI grant and Conacyt (via
UNAM)• Initial availability to astronomers anticipated this
summer 20Goal: increase peak bandwidth to 4 Gbps
VLBA 運用継続問題 NSF : VLBA 運用経費(6 M$/yr) 半分以上を
non-NSF fund で運用しないと 2011 年 10 月からBudget cut
2011 年 2 月 VLBA future WS• サポートの目標 (3M$/yr)
NRAO 1M$/yr 自助努力 ○ Naval Obs. 1M$/yr -> daily UT1 決定 ○ FERMI 0.15 M$/yr Shanghai 0.2 M$/yr ○ ASISS 0.2 M$/yr ○ MPIfRA 0.2 M$/yr 申請中 CSIRO/ICRUR 0.15 M$/yr NAOJ 0.2 M$/yr
VLBI 長期計画の必要性 国内問題
• Astro-G の中止 次期スペース VLBI を提案するのか、しないか? AGN などの研究をどのように発展させるのか?
国際的な VLBI ロードマップの必要性• 多波長や電波の他分野に対する VLBI の存在意義の明確化
ALMA 、 SKA との関係 VLBI Large program の戦略
• Global array 構想の浮上 VLBA の運用スキームの変更
東アジア VLBI 観測網の開始• VLBA/EVN などとの棲み分け
位相補償・高い周波数・・・・
長期計画の策定について 研究目的を明確にする
• 研究目標の設定 • 実現性(装置性能・マンパワー)の検討
開発計画を明確にする• 周波数バンド• 記録帯域• eVLBI
予算計画
来年の EAVN シンポに向けて Need considerations by each countries and
groups• White papers of research subjects (What do we
want?)• Development schedule (What can we do?)• Realistic operation plan (How much can we do?)
Need to start activities of Road map creation• Science goal• Development scope• Operation scheme
ALMA project
15th of August: 18 antennas at the AOS
ALMA Cycle - 0 time allocation
ALMA Schedule
2011 Sep. Start of Early Science
2013 Mar. 開所式 2014 Jan. 66 台フル運用 Antenna
• 2012 2nd Quarter : EA 16 台完• 2013 1st Quarter : NA 25 台完• 2013 3rd Quarter : EU 25 台完