Cycle 1 Capability
齋藤 正雄（国立天文台）
East Asian ALMA Project Scientist
2011/12/26
ALMA Cycle 1 Capability@ALMA
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初期運用コンセプト
• ALMA Early Science Cycle 0
– is expected to span 9 months.
– allocates 550 hours of array time for Early
Science projects.
• ALMA Early Science Cycle 1
– is anticipated that1300 hours of array time will be
available for Early Science projects.
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Cycle 0 仕様
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•
•
•
16 x 12m antenna array
18-125m, 36-400m baselines, 2 configurations
Single field imaging and Mosaics up to 50 fields
Frontend
–
–
–
–
Band 3 (2SB: 84GHz - 116GHz)
Band 6 (2SB: 211GHz - 275GHz)
Band 7 (2SB: 275GHz - 373GHz)
Band 9 (DSB: 602GHz – 720GHz)
• Set of ~14 spectral modes (see later)
• No single dish, No polarization, No special modes
• Amp Calibration good to 5% (band 3) and less accurate
at high frequencies
• The goals are: better than 10% in bands 6 and 7, and
better than 20% in band 9.
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Cycle 1 仕様（もうすぐ確定）
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•
•
•
•
•
•
•
32 x 12m antenna + 6 x 7m antenna array
Max baseline ~ 150-1000 m
Single field imaging and Mosaics up to 150 fields
Frontend
–
–
–
–
Band 3 (2SB: 84GHz - 116GHz)
Band 6 (2SB: 211GHz - 275GHz)
Band 7 (2SB: 275GHz - 373GHz)
Band 9 (DSB: 602GHz – 720GHz)
Cycle 0+Independent setup for each baseband
Total Power Observations
No polarization, No solar observation, No spectral sweep
ToO, Monitoring program.
• PIs will apply for a required angular resolution and
largest angular scale rather than specific configurations.
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Cycle 1観測で可能になりそう
• アンテナ 12mアンテナｘ32台
– Cycle 0と比べ高感度、サイドローブ小さい
• 最長基線長1000m
– 最高分解能0”.17 at 345 GHz
• 7mアンテナ6台、単一鏡2台（広がった成分取得）
– 7mアンテナは１つの配列、7mアンテナのみの観測は受
け付けない
– 単一鏡は輝線観測のみ、連続波は受け付けない
– 単一鏡・干渉計コンバインはfeatheringのみ保証、joint
deconvolutionの提供は確約できない
• 各ベースバンドで違う周波数分解能設定
– 連続波と輝線観測でそれぞれの最適化が可
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分光観測について補足
• Cycle 0と基本的には同じモードを提供、
• 各ベースバンドで独立した周波数分解能設
定が可能、周波数設定の自由度向上
• サイドバンド分離の向上
• ベースバンド内サブバンドでの複数周波数分
解能設定は不可
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Cycle 0では同じ周波数分解
能設定のみ可能
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Cycle 1では別の周波数分解
能設定も可能
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Cycle 0とCycle 1の比較
Cycle0
Cycle 1
12m アンテナ
7mアンテナ
16
なし
32
6
単一鏡
なし
2台：輝線
最長基線長
400
1000 m
バンド
3,6,7,9
3,6,7,9
モザイク
50
150 field
偏波、太陽、輝線掃査観測
なし
なし
周波数設定
４ベースバンドで同設定
４ベースバンドで独立設定
天体数
制限なし
1 SGにつき15天体(15度以内）
1 SGにつき5天体(15度以外）
周波数設定数
制限なし
1 SGにつき5セット
プロポーザルのSG数
制限なし
1プロポーザルにつき5 SG
SG: Science Goal: 赤字は変更の可能性あり
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空間分解能
Extended Configuration (最大基線長1000mを仮定）
Angular
Field of
Band Frequency
Resolution
View
GHz
Arcsec
Arcsec
3
100
0.62
62
6
230
0.27
27
7
345
0.17
18
9
670
0.10
9
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周波数分解能と帯域
Time Division Mode (TDM) or Frequency Division Mode (FDM).
At 100 GHz
0.05 km/s
0.1 km/s
0.2 km/s
0.4 km/s
0.8 km/s
1.6 km/s
Effective spectral resolution is twice as channel spacing.
各ベースバンドで上記の組み合わせが自由にできる
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特別観測
• 下記についてはCycle 1で提供しないが、試験的に実施。
データは検証後公開へ。試験参加等に興味ある方は齋藤
まで連絡を
• 偏波観測
– ターゲット：連続波、直線偏波、全強度の1%の精度
– 拡張ターゲット：輝線、モザイク、円偏波
• 太陽観測
– 単一鏡による活動領域の画像化、モニター
– 時間分解能1秒での干渉計観測
– 天体の強度校正精度は厳しい
• バンド4、バンド8（ACA-stand alone）
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Cycle 1 Programs
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Standard Programs
Target of Opportunity
Discretional director’s Time
Time critical – scheduling of 1-2 week
Large programs not offered.
Highly rated Cycle 1 projects not observed
in Cycle 1 will NOT be transferred to Cycle
2.
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Summary
• ALMA Early Science Cycle 0 just started
and Cycle 1 CfP is planned to be issued in
2012Q1 or Q2.
• More capabilities expected for Cycle 1
than Cycle 0.
• Prepare for your proposal with
understanding ALMA Cycle1 capability.
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www.almaobservatory.org
The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership among Europe, North
America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for
Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in
cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in Japan by the
National Institutes of Natural Sciences (NINS) in cooperation with the Academia Sinica (AS) in Taiwan. ALMA construction and
operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which
is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ).
The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of
ALMA..
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