2012/6 Town Meeting Cycle1 Capability, Policy, & Scince Case 1 ALMA Early Science ” Cycle1” Capability, Policy & Science Case Kazuya Saigo, Eiji Akiyama,

2012/6 Town Meeting Cycle1 Capability, Policy, & Scince Case 1

ALMA Early Science ” Cycle1” Capability, Policy & Science Case

Kazuya Saigo, Eiji Akiyama, Yasutaka Kurono, Yuichi Matsuda (NAOJ Chile Observatory)

M100 (CSV result 12m array + ACA)

This Talk• ALMA Overview • ALMA Early Science Cycle 1 Capability I

　 Basic (Frequency/Sensitivity/Resolution)• ALMA Early Science Cycle 1 Capability II

　 Observational Modes/Limit• ACA • ALMA Science


AAtacamatacama LLargearge MMillimeter/submillimeter illimeter/submillimeter AArrayrray at 5000 m high site in northern Chile • ALMA is in construction phase now. Early Science Phase (Construction phase) 2011 Cycle 0 operation 2012 Cycle 1 operation … we are here! 2013 Cycle 2 operation Inauguration (The end of a construction phase) Full Operation Phase (All observation modes become available.) - Main Array: 12m x 50 Antennas 　 - Atacama Compact Array: 12m x 4 + 7m x 12

• Even in cycle1 phase , ALMA achieves with the highest sensitivity and the highest spatial resolution in observation at submillimeter wavelength. • The ALMA Project is a joint project among East Asia, Europe, and North America in cooperation with Chile.

ＡＬＭＡ Project OverviewWhat is ALMA Project.

BBC (C) 2012


ALMA Early Science Cycle 1 Timeline

Timeline- 31 May, 2012 (15:00UT) Call for Proposal

Opening of the Archive for proposal submission

- 12 July 2012 (15:00 UT)Proposal submission deadline- November 2012 Announcement of the outcome of the

Proposal Review Process

- 1 January 2013 　　 Start of ALMA Cycle 1 Science Observations- （ May 2013 　 Expected deadline for proposal submission for Cycle 2 )

- 31 October 2013 　　 End of ALMA Cycle 1

Total observation time in Cycle1 - 800 hours for 12m main array- Up to 800 hours for ACA system 　 (see later)- About 200 highest priority projects are expected to be prepared for

scheduling.

Cycle 1 timeline

←　 we are here!


1. Band (Frontend Detector) example line - Band 3 (2SB: 84GHz - 116GHz) : CO(1-0), HCO+(1-0), CS(2-1), N2H+(1-0),,,

- Band 6 (2SB: 211GHz - 275GHz) : CO(2-1), HCO+(3-2), CS(5-4), N2D+(3-2),,,, - Band 7 (2SB: 275GHz - 373GHz) : CO(3-2), HCO+(4-3), CS(6-5/7-6), N2H+(3-2), N2D+(4-3),

- Band 9 (DSB: 602GHz - 720GHz): CO(6-5), HCO+(7-6/8-7), CS(13-12/14-13), H2D+(8-7/9-8), H2S,

Cycle 1 Basic Capability – Spectral Setting -

2. Frequency Resolution & Setting (Correlator) - We can select spectral setting from 15 spectral modes for each line. Effective Channel Number: 3840 (x 2 pol.) for each spectral line Frequency resolution: 30.5kHz ～ 976.5kHz (⇔ Bandwidth=58.6MHz ～ 2GHz)

Bandwidth

(MHz)

Channel spacing

(MHz)

Spectral Resolution (MHz) 　　　 ↓ dv at 100GHz

Number of channels

Correlator mode

2000 15.6 31.2 (93.7km/s) 128 TDM

1875 0.488 0.976 (2.93km/s) 3840 FDM

938 0.244 0.488 (1.46km/s) 3840 FDM

469 0.122 0.244 (0.732km/s) 3840 FDM

234 0.061 0.122 (0.366km/s) 3840 FDM

117 0.0305 0.061 (0.183km/s) 3840 FDM

58.6 0.0153 0.0305 (0.091km/s) 3840 FDM

Correlator Modes, dual-polarization (Proposers Guide A5)

27km/s

0.85km/s

0.42km/s

0.21km/s

0.11km/s

0.053km/s

0.027km/s

Velocity Resolution at 345GHz

Cycle 1 Basic Capability




- Band 9 (DSB: 602GHz - 720GHz): CO(6-5), HCO+(7-6/8-7), CS(13-12/14-13), H2D+(8-7/9-8), H2S,2. Frequency Resolution & Setting (Correlator) - We can select spectral setting from 15 spectral modes for each line. Effective Channel Number: 3840 (x 2 pol.) for each spectral line Frequency resolution: 30.5kHz ～ 976.5kHz (⇔ Bandwidth=58.6MHz ～ 2GHz) - ALMA can observe 4 spectral lines with different frequency resolution simultaneously.

Frequency Band which can be observed simultaneously

Band 7

Band 7 example1

Upper SidebandLower Sideband

• CO (3-2) = 345.8GHz BW=938MHz (dv=0.42km/s)

• H13CO+(4-3) = 347.0GHz BW=469MHz (dv=0.21km/s)

• HCO+(4-3) = 356.7GHz BW=469MHz (dv=0.21km/s)

• Continuum = 358GHz BW = 2000MHz






- Band 9 (DSB: 602GHz - 720GHz): CO(6-5), HCO+(7-6/8-7), CS(13-12/14-13), H2D+(8-7/9-8), H2S,2. Frequency Resolution & Setting (Correlator) - We can select spectral setting from 15 spectral modes for each line. Effective Channel Number: 3840 (x 2 pol.) for each spectral line Frequency resolution: 30.5kHz ～ 976.5kHz (⇔ Bandwidth=58.6MHz ～ 2GHz) - ALMA can observe 4 spectral lines with different frequency resolution simultaneously.

Band 7

Band 7 example2


Continuum emission only (single continuum mode)

Bandwidth=8GHz (2GHz x4)



Band 7




- Band 9 (DSB: 602GHz - 720GHz): CO(6-5), HCO+(7-6/8-7), CS(13-12/14-13), H2D+(8-7/9-8), H2S,

Cycle 1 Basic Capability – Sensitivity & Resolution -

2. Frequency Resolution & Setting (Correlator) - We can select spectral setting from 15 spectral modes for each line. Effective Channel Number: 3840 (x 2 pol.) for each spectral line Frequency resolution: 30.5kHz ～ 976.5kHz (⇔ Bandwidth=58.6MHz ～ 2GHz) - ALMA can observe 4 spectral lines with different frequency resolution simultaneously.

4. Spatial Resolution (Configurations) 6 configurations Maximum baseline = 166m ～ 1 km

3. Sensitivity (Number of Antennas) Main Array: 32 x 12m antennas Additional subarray: 7 x 7m anntenas + 2 x 12m single dish (ACA system) New! 　

Sensitivity in Cycle1 = x 2 of Cycle0

The maximum spatial resolution becomes 2.5 times higher than that in cycle 0. 　

Image quality improves!



※ 天体からの電磁波を相関機で干渉させると、ビジビリティー（ visibility, 干渉縞の明暗強度 ) が得られます。簡単のために１次元 uで考えると、

　

となります ( 実際は２次元 ) 。逆フーリエ変換し天体輝度分布 I(r) を得ます。

r)r2exp()r()(Source

*21 diuIu aa

干渉計観測天球上の位置ベクトル r

天球

相関機

最大18km

干渉計は普通の観測と違い、天体からのフラックス強度分布のフーリエ分解成分を観測し、それを逆フーリエで画像に戻します※。　　

Point 1: アンテナ間距離（基線）が長いアンテナペアで観測すると空間周波数が高い　（小さな空間スケールのフーリエ成分）情報が得られます ( 最大基線長⇔空間分解能 ) 。

　

Point 2: 最短基線長間の相関からはもっとも低い空間周波数情報が得られます。より低い空間周波数情報は得られないため、より広がった空間構造成分は干渉計観測画像から落とされます ( 最短基線長⇔ Resolve Out) 。 flux 強度絶対値の不定性となります。

　

Point 3: 単一鏡電波観測と異なり、干渉計観測では１つの座標の観測でも画像が得られます。画像サイズはアンテナ口径で決まり各アンテナの視野 (=Beam Size) と同じです。

Spatial Resolution: 　　　　　　　　　　　　　　　　　　　　　　　 : 観測周波数、Lmax: 最大基線長

Lmax

m250345GHz0.72" 　

Resolve Out スケール：　　　　　　　　　　　　　　　　　　　　 : 観測周波数、 Lm

in:( 実効 ) 最短基線長

Lmin

m18345GHz 10.0" 　　

視野サイズ（画像サイズ）：　　　　　　　　　　　　　　　　　 : 観測周波数、 Dan

tenna: アンテナ口径

antennaD

m12345GHz 14.9" 　　

参考


Cycle 1 Basic CapabilitySensitivity Examples1 (Continuum emission)

BW=8GHz, t = 60 min 1sensitivity Point Source Most Compact Conf. Most Extended Conf.Band 3 (100GHz) : 13 J 0.12mK (3.7”) 5.1mK (0.57”)Band 6 (230GHz) : 17 J 0.15mK (1.6”) 6.2mK (0.25”)Band 7 (345GHz) : 29 J 0.25mK (1.1”) 12mK (0.16”)Band 9 (675GHz) : 220 J 2.0mK (0.55”) 92mK (0.08”)



Cycle 1 Basic CapabilitySensitivity Examples2 (Line emission)

・ Sensitivity and Spatial Resolution in Cycle1

TW Hya is neayby protoplanetary disk (d=50pc).This is HCO+(4-3) maps from TW Hya, with white continuum contours at 3 and 100 sigma.

・ ALMA Science Verification Data (TW Hya)

integrated intensity, intensity weighted velocity field,

Most Extended, d=0.244MHz, t = 60 min Beam Size 1Band 3 (100GHz) : 0.57”, 0.92 KBand 6 (230GHz) : 0.25”, 1.13 KBand 7 (345GHz) : 0.16”, 2.11 KBand 9 (675GHz) : 0.08”, 16.7 K

In Cycl1, ALMA enable us to obtain the emission line image map of nearby protoplanetary disks with the spatial resolution of a 0.1" order.

Most Compact, d=0.244MHz, t = 60 min Beam Size 1Band 3 (100GHz) : 3.7”, 22 mKBand 6 (230GHz) : 2.6”, 28 mKBand 7 (345GHz) : 1.1”, 45 mKBand 9 (675GHz) : 0.55”, 353 mK



　Most Compact Configuration Case (Lmax=160m, t = 10min)

Beam@345GHzUV Plane@345GHzAntenna Configuration

Side lobes: below 10%!

Cycle 1 Basic CapabilityUV plane/Beam Pattern

Beam@345GHzUV Plane@345GHzAntenna ConfigurationMost Extend Configuration (Lmax=1000m, t = 10min)

Side lobes: below 10%!


x (m)

x (m)

y (

m)

y (

m)


・ Observation Mode- No sub-array- Mosaic (up to 150 field) - No Polarization - No solar Observation

・ Operation - Target of Opportunity (ToO) and Director Discretionary Time (DDT) Like standard proposals, these proposals must be submitted by the Cycle 1 proposal deadline. - Only a few ToO proposals are likely to be among the highest ranked Cycle 1 proposals. The reaction time for its execution from triggered may be as long as 3 weeks. Shorter reaction times (few days) may be possible but are not guaranteed.

・ ACA (Atacama Compact Array) ACA(7m array + Single Dish) operation start!

ALMA Early Science Cycle1 Capability - Observing Mode/Operation -

M100

Mosaic (149 fields) at =115GHz Rectangle fie

ld 300”x280”


• Up to five Science Goals per proposal. * Science Goal: an Observational Setting (Spectral Setting/Sensitivity)

• Limitation of Target Number– Up to 15 individual sources (within 15 degrees on the sky) in a single

Science Goal – no more than five separate velocities in a single Science Goal

• We can set multi-points observation to each target.

But total number of positions (fields) in each proposal should be less than 151.

• The maximum observing time per proposal is 100 hours (Standard Program)

• Cycle 1 observations will be scheduled mainly during nighttime.• All Cycle 1 Early Science observing will be conducted on a best effort

basis. • Cycle 1 projects that have not been completed by the end of the cycle

will not be carried over to Cycle 2.

14

ALMA Early Science Cycle1 Capability - Additional Limitations -

Target Position

PointingFields

X

Cycle 1 Obs. Modes


What does five separate velocities mean? Proposers Guide A6.2. Multiple sources (3) can be observed with no more than five separate velocities that all fall within the same receiver band.

Example: CO (5-4) line (rest freq. = 576GHz)

参考　

Band7target No.1 (z=1.00)

target No.2 (z=1.05) target No.3 (z=1.10)

OK unallowable

LO setup is allowed to five about red shift of lines (in the same band) per science goal.

Band7 Band6


Accuracy

ALMA observatory provides calibrator (PI can define it).

• Accuracy of Absolute Amplitude Calibration – Band 3: good to 5%– Band 6/Band 7: good to 10% – Band 9 : good to 20% (Goal)

• Positional Accuracy about 1/10th of synthetic beam size (It depends on noise level when a S/N ratio is low. )　


ACA (Atacama Compact Array) ACA is the tool for imaging of spread structure correctly. By combining the data of 12-m array and ACA array, we can recover Resolve Out which is a weak point of an interferometer with keeping high spatial resolution.

12-m Array Configuration

Min Baseline(meters)

Max Baseline1

(meters) ACA Allowed?

C32-1 15 166 Yes

C32-2 15 304 Yes

C32-3 21 443 Yes

C32-4 21 558 Yes

C32-5 26 820 No

C32-6 43 1091 No

• ACA System in Cycle1– 9 x 7m antennas array 　

One configuration (baseline = 8.5m ～ 43m Baseline) – 2 ～ 3 台 x12m Single Dish (TP: Total Power Array)

• ACA Cycle 1 Capability – In Cycle 1, we can use ACA in compact 12-m Array configurations

(tminimum baselines less than 25 m = Lmax < 558m) . – TP array can not observe continuum emission.

(7m-array can observe continuum) – Observation time of ACA

3 x (12-m Array observation time) 　


※ 天体からの電磁波を相関機で干渉させると、ビジビリティー（ visibility, 干渉縞の明暗強度 ) が得られます。簡単のために１次元 uで考えると、

　

となります ( 実際は２次元 ) 。逆フーリエ変換し天体輝度分布 I(r) を得ます。

r)r2exp()r()(Source

*21 diuIu aa

干渉計観測天球上の位置ベクトル r

天球

相関機

最大18km

干渉計観測とは、天体からのフラックス強度分布のフーリエ分解成分を観測する装置。それを逆フーリエ変換で画像に戻します※。　　

Point 1: アンテナ間距離（基線）が長いアンテナペアで観測すると空間周波数が高い　（小さな空間スケールのフーリエ成分）情報が得られます ( 最大基線長⇔空間分解能 ) 。

　

Point 2: 最短基線長間の相関からはもっとも低い空間周波数情報が得られます。それより低い空間周波数情報は得られないため、広がった空間構造成分は干渉計観測画像から欠落します ( 最短基線長⇔ Resolve Out) 。

　

Point 3: 単一鏡電波観測と異なり、干渉計観測では１つの座標の観測でも画像が得られます。画像サイズはアンテナ口径で決まり各アンテナの視野 (=Beam Size) と同じです。

Spatial Resolution: 　　　　　　　　　　　　　　　　　　　　　　　 : 観測周波数、Lmax: 最大基線長

Lmax

m250345GHz0.72" 　

Resolve Out スケール：　　　　　　　　　　　　　　　　　　　　 : 観測周波数、 Lm

in:( 実効 ) 最短基線長

Lmin

m18345GHz 10.0" 　　

視野サイズ（画像サイズ）：　　　　　　　　　　　　　　　　　 : 観測周波数、 Dan

tenna: アンテナ口径

antennaD

m12345GHz 14.9" 　　

参考





Max Baseline1


C32-1 15 166 Yes

C32-2 15 304 Yes

C32-3 21 443 Yes

C32-4 21 558 Yes

C32-5 26 820 No

C32-6 43 1091 No


Single configuration (baseline = 8.5m ～ 43m Baseline) – 2 antennas x12m Single Dish (TP: Total Power Array)


(tminimum baselines less than 25 m = Lmax < 558m) . – TP array can not observe continuum emission.

(7m-array can observe continuum) – Observation time of ACA

3 x (12-m Array observation time) 　


Very Large Telescope (VLT)FORS

ALMAband 3, CO(1-0) moment 1

http://almascience.eso.org/almadata/sciver/M100Band3/

ALMA Science Verification Data: M100

12m main array only

Demonstration of Data Combine (M100) ACA 例


Demonstration of Data Combine (M100)CO(1-0) Moment Map

7m array 12m Total Power (single dish)On the fly mapping

12m array (Main array)

+

ACA 例


Very Large Telescope (VLT)FORS

http://almascience.eso.org/almadata/sciver/M100Band3/

12m array

Demonstration of Data Combine (M100)

ALMAband 3, CO(1-0) moment 1Recovering by ACA

12m array only

12m array + ACA

Velocity [km/s]

mJy

/Bea

m

CO(1-0) line profile

ACA 例





Max Baseline1


C32-1 15 166 Yes

C32-2 15 304 Yes

C32-3 21 443 Yes

C32-4 21 558 Yes

C32-5 26 820 No

C32-6 43 1091 No


Single configuration (baseline = 8.5m ～ 43m Baseline) – 2 antennas x12m Single Dish (TP: Total Power Array)


(tminimum baselines less than 25 m = Lmax < 558m) . – Observation time of ACA

3 x observation time of 12m main array → Total observation time = obs time of 12m main array + obs time of ACA

– TP array can not observe continuum. (7m-array can observe continuum) 　　


Angular resolution and Maximum Angular Scale for the six Cycle 1 12-m Array configurations (Proposers Guide Table A.2)

参考

たとえば、- 周波数 345GHz の観測-空間分解能 0.4”を要求する。

つまり、 12m アンテナ配列 C32-3 が観測で使われる配列である。

この配列では、 5” を超える空間スケール構造は Resolve Out する（観測できない）。そのような観測には ACA を使うことが必要となる。

周波数、分解能、 Largest Scale の値から、 OT が ACA が必要かどうかをsuggestion してくれる。

ただし！！Extended な配列（高空間分解能 )では ACA は利用できません。Proposers Guide A.3 参照

具体的に、 ACAが必要かどうかを調べる方法


Angular resolution and maximum angular scales for continuum4 observations using the allowed 12-m Array & ACA combinations (Proposers Guide Table A4)

Angular resolution and Maximum Angular Scale for the six Cycle 1 12-m Array configurations (Proposers Guide Table A.2)

参考ACAには連続波観測に関しても制約がある。

ACAのうち、連続波観測が出来るスケールを調べる方法

ACA のうち single dish (TP array) は連続波を観測できない (7m array は可能 ) 。　

逆に言うと、 TP array のデータを使わないで済む空間スケールまでは連続波観測可。

つまり、 13” までは連続波観測が出来る (7m array + 12m array で事足りる ) 。


Shadowing fraction vs. Declination for the two most compact configurations of the 12-m Array and for the 7-m Array with a track duration of 2 hours (±1h HA).

Shadowing


Weather Condition

The numbers indicate the percentage of time when the pwv is below 1 mm as a function of Local Sidereal Time (LST) and week number beginning with January 1, 2013.

ALMA Band Band 3 Band 6 Band 7 Band 9

Fraction of time 100% 70% 40% 10%

Estimated maximum fraction of Early Science observing time suitable for observations in each band in Cycle 1

local midnight

shuotdown ALMA engineering time

Cycle 1 observations will be scheduled mainly during nighttime.


Summary of Cycle1 Capablity

• Call for Proposal is scheduled the end of May. Proposal submission deadline is scheduled 12th of July.

• Total observation time of 12m main array is 800hours.• Compared with Cycle0,

The sensitivity: x 2 The maximum spatial resolution: x 2.5 (1.2" - 0.19" @345GHz).

• ACA is available. Band Frequency

(GHz)

Angular Resolution Maximum Scale

Flux *1

(mJy)

Tb *2

(K)

Field of View

3 100 0.57” (3.7”) 8.6” (25”) 0.06 2.4 (0.056) 62”

6 230 0.25” (1.6”) 3.7” (11”) 0.09 1.9 (0.047) 27”

7 345 0.16” (1.1”) 2.5” (7.1”) 0.15 2.9 (0.062) 18”

9 670 0.08” (0.55”) 1.3” (3.6”) 1.10 16 (0.35) 9”

Summary of Most Extended Configuration Lmax= 1km

1: 5 sigma continuum sensitivity (Bandwidth=8GHz) for 1hr2: 3 sigma line sensitivity for 1 hr (1 km/s)

( )<=Most Compact Lmax=160m



ALMA によるサイエンス例


© ALMA (ESO/NAOJ/NRAO). Visible image: the NASA/ESA (HST)

The narrow dust ring around Fomalhaut(Boley +12, Cycle0 paper)

Optical images trace micron-sized grains, which are strongly affected by stellar radiation. Radio continuum trace millimeter-sized grains, which trace parent bodies. => ALMA high spatial resolution observation.

ALMA obs. Suggest that debris confined by shepherd planets is the most consistent with the ring’s morphology.


Distributions of Deuterated Molecules in TW Hya Protoplanetary Disk

(Oberg +12, science verification)

ALMA (SV band6) SMA (Qi et al. 2008)

TW Hya is neayby protoplanetary disk (d=50pc).This is HCO+(4-3) maps from TW Hya, with white continuum contours at 3 and 100 sigma (CASA home page).

integrated intensity, intensity weighted velocity field,


[CII]158um emission at z=5(Wagg+12, science verification)

L[CII] = 10.0 x 109 L⊙ L[CII] = 6.5 x 109 L⊙

[CII]-to-FIR ratio ~ 0.1 – 1%

The total observing time 25 min (on-source)

• [CII] line detection in a pair of gas-rich galaxies

Follow up observation of K.Ohta +96, Iono +06

20h SMA obs. => only 3 sigma (Iono + 06)


[NII]205um emission at z=5(Nagao+12, cycle 0 paper)

• The first measurement of the [NII]/[CII] flux ratio in high-z galaxies (SMGs are chemically evolved)

Total observing time 3.6hrs



Materials


Cycle1 Continuum emission （ Bandwidth = 8GHz ）　 Sensitivity

Most Compact (L=160m)

Cycle 1 ( ３２ 12m array) t = 60 min 　 Dec 　　　 = -30deg

Most Extended(L=1km)


Review Process• プロポーザルは、 5 つの Categories に分けられる。• 各 Category にある Review Panel に振り分けられ、科学的審査される。 ※ 各 Category には 2 つ程度の Review Panel( ６名程度 ) が作られる。• High priority proposal になる可能性が高いものは技術審査を受け、観測実現不可な Proposal を除く。• 全プロポーザルで採点の高い順から High priority proposal を採択する。

　ただし、以下の割合となるようにされる。-22.5% for East Asia (EA);-33.75% for Europe (EU);-33.75% for North America (NA);-10% for Chile.

Review Panel による審査は 11 月に行われる予定である。


観測デモンストレーションALMA が提供する CASA( 解析ツール ) には観測シミュレー

ターが付随している。視直径 0.8sec のタイタンを例にCycle1 での空間分解能をデモンストレーションすると、

Titan 表面の HST 画像よりモデル作成(Smith et al. 1996)

最大 160m 基線長 (@345GHz)

最大 1000m 基線長 (@345GHz)

( 注意 ) 今回は画像変換のデモンストレーション


Band 7 example

Example 4 spectral lines (4 spectral windows)• CO (3-2) = 345.80GHz Bandwidth=937.5MHz (d= 488.kHz ⇔ dv = 0.42km/s)• H13CO+(4-3) = 347.00GHz Bandwidth=468.8MHz (d= 244.kHz ⇔ dv = 0.21km/s)• HCO+(4-3) = 356.73GHz Bandwidth=468.8MHz (d = 244.kHz ⇔ dv = 0.21km/s) • Continuum emission = 358GHz Bandwidth = 2000MHz


Frequency Band which can be observed simultaneously

(GHz)

Band 7

ALMA Early Science Cycle1 Capability - Frequency setting (Examples1)-

2012/6 Town Meeting Cycle1 Capability, Policy, & Scince Case 1 ALMA Early Science ” Cycle1” Capability, Policy & Science Case Kazuya Saigo, Eiji Akiyama,

Documents

end of alma cycle

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6mhz2ghz alma

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