Early Science Specification and Expected Array Evolution Masao Saito EA ALMA Project Scientist EA PS Report1 2nd ALMA Users Meeting 2011/1/13

Contents Early Science Specification –Minimum Requirement –Stretch Galleries Summary EA PS Report 2nd ALMA Users Meeting 2011/1/13 2

EA PS Report3 ALMA 5 antennas at AOS (2010.6) 2nd ALMA Users Meeting 2011/1/13 9 operational antennas at AOS as of

Early Science Concept ALMA Early Science Cycle 0 –is expected to span 9 months. –is anticipated that hours of array time will be available for Early Science projects. –Any astronomer may submit a proposal in response to the ALMA Early Science Cycle 0 Call for Proposals. –Proposals that best demonstrate and exploit the advertised ALMA Early Science Cycle 0 capabilities, producing scientifically worthwhile results from relatively short observations (averaging a few hours), will be given preference. EA PS Report 2nd ALMA Users Meeting 2011/1/13 4 Important to understand capability in writing a proposal

Cycle 0 Minimum Spec 16 x 12m antenna array m baselines, 2 configurations Single field imaging Frontend –Band 3 (2SB: 84GHz - 116GHz) –Band 6 (2SB: 211GHz - 275GHz) –Band 7 (2SB: 275GHz - 373GHz) –Band 9 (DSB: 602GHz – 720GHz) Set of ~21 spectral modes (see later) No subarrays, no special modes Amp Calibration good to 5% (band 3) and less accurate at high frequencies – 15% at band 9? EA PS Report5 2nd ALMA Users Meeting 2011/1/13

Cycle 0 Capabilities - Stretch To be decided by ~ mid-March 2011 Polarization: Full Stokes parameters on compact sources: Q, U and V accurate to 1% of I. Pointed Mosaics – up to 25 points Zero-spacing (single-dish rasters maps) – to cover same area as mosaics – Spectral Line only. Baselines up to 500m, 3 configurations (or perhaps some other scheme to give us longer baselines late in the first cycle). EA PS Report6 2nd ALMA Users Meeting 2011/1/13

Spectral modes for Cycle 0 TDM modesPoint Spacing 1 (MHz) → Band-MHz width “ASAC” modes in red FDM modesSpacing of spectral points 1 (kHz)→ Band-MHz width ↓ FDM: Digitization efficiency is ~85% TDM: Digitization efficiency is ~88%. Same mode for 4 basebands with 122 kHz 1.77 times worse ~ 0.3 mJy /hr at 345 GHz EA PS Report7 2nd ALMA Users Meeting 2011/1/13

EA PS Report 2nd ALMA Users Meeting 2011/1/13 8 1) Spatial Resolution and Field of View Resolution Field of View 2) Sensitivity ES cycle0 Resolution Early Science

Spatial Resolution Max baseline of SMA ～ 600m ALMA ES (cycle0) ～ 250m 感度 （ 2GHz Bandwidth 1  345GHz) SMA integ time(WV 2.50mm) τ=4.0hr ALMA integ time(WV 1.26mm) τ=18.4sec ※ (SMA ALMA OT IT3) ALMA needs1/780 integtime of SMA Similar to SMA extended Configuration Cycle0 Sensitivity (Comparison with SMA) SMA EA PS Report9 2nd ALMA Users Meeting 2011/1/13

SMA 6hr(on source 4hr) Extended configuration ALMA 5min integ time 250m configuration Contour every 5 % 20% level SMA サイト で計算 Contour every 10 % Similar beam size with similar sidelobe level Cycle0 PSF (Comparison with SMA) EA PS Report10 2nd ALMA Users Meeting 2011/1/13

Example EA PS Report 2nd ALMA Users Meeting 2011/1/13 11 Early Science 1hr integ 5sigma detection limit JCMT Disk Survey in Taurus by Andrews+05

Cycle 0: UV coverage and PSF UV coverage and PSF by CASA image simulator with 5 min and 8 hr integration ALMA site: latitude = -23 degrees 16 12m antennas Max Baseline 250m Tentative Array Configuration Antennas (Blue dots) and Pads (pink dots) 120 baseline UV Plane FOV ~14.9 arcsec ＠ 345GHz EA PS Report12 2nd ALMA Users Meeting 2011/1/13

Taurus(04h30m,25d00m) の コントアは 0.05(5%) 刻み 5 minutes integration 8 hours integration beam FWHM(0.62”,0.92”) PA ～ -20deg side-lobe -2% ～ 20% 1σ sensitivity (2GHz BW) 0.86mJy (17.2mK) beam FWHM(0.69”,0.85”) PA ～ 40deg side-lobe -4% ～ 6% 1σ sensitivity (2GHz BW) 0.088mJy (1.71mK) EA PS Report13 2nd ALMA Users Meeting 2011/1/13

Orion(05h35m,-5d00m) の コントアは 0.05(5%) 刻み 5 minutes integration 8 hours integration beam FWHM(0.58”,0.69”) PA ～ -40deg side-lobe -6% ～ 20% 1σ sensitivity (2GHz BW) 0.79mJy (22.3mK) beam FWHM(0.62”,0.73”) PA ～ -60deg side-lobe -6% ～ 8% 1σ sensitivity (2GHz BW) 0.080mJy (2.03mK) EA PS Report14 2nd ALMA Users Meeting 2011/1/13

 -Oph. (16h25m,-25d00m) の コントアは 0.05(5%) 刻み 5 minutes integration 8 hours integration beam FWHM(0.58”,0.65”) PA ～ -40deg side-lobe -6% ～ 20% 1σ sensitivity (2GHz BW) 0.78mJy (23.3mK) beam FWHM(0.58”,0.73”) PA ～ -75deg side-lobe -6% ～ 8% 1σ sensitivity (2GHz BW) 0.079mJy (2.70mK) EA PS Report15 2nd ALMA Users Meeting 2011/1/13

Lupus (15h40m,-35d00m) の コントアは 0.05(5%) 刻み 5 minutes integration 8 hours integration beam FWHM(0.58”,0.65”) PA ～ -40deg side-lobe -6% ～ 20% 1σ sensitivity (2GHz BW) 0.78mJy (23.5mK) beam FWHM(0.58”,0.73”) PA ～ -75deg side-lobe -6% ～ 6% 1σ sensitivity (2GHz BW) 0.080mJy (2.14mK) EA PS Report16 2nd ALMA Users Meeting 2011/1/13

Chameleon (15h40m,-70d00m) の コントアは 0.05(5%) 刻み 5 minutes integration 8 hours integration beam FWHM(0.62”,0.88”) PA ～ -30deg side-lobe -6% ～ 20% 1σ sensitivity (2GHz BW) 0.86mJy (17.9mK) beam FWHM(0.73”,0.73”) PA ～ -75deg side-lobe -4% ～ 4% 1σ sensitivity (2GHz BW) 0.088mJy (1.86mK) EA PS Report17 2nd ALMA Users Meeting 2011/1/13

Gallery1 EA PS Report 2nd ALMA Users Meeting 2011/1/13 18 This is an object in our own galaxy. It is a young star which is still surrounded by a disc of gas. Here we are observing the carbon monoxide J = 3-2 line at 345 GHz in the disc. (The star itself is not visible here.) The integrated flux is shown as contours on the left, while the spectrum at the peak of the emission is on the right, showing, via the Doppler effect, that the gas is moving at different speeds. In the middle is the average velocity of the gas at each point in the image, indicated by the colour. This shows a characteristic pattern created by the rotation of the disc around the star.

Gallery2 EA PS Report 2nd ALMA Users Meeting 2011/1/13 19 As a test of ALMA’s ability to observe broad spectral lines, we observed the quasar BRI , which is at a red-shift of z = The object is again unresolved on short baselines, but the 158 micron line from ionized carbon is clearly detected in the spectrum, which is impressive given that this observation took only one hour in total.

Summary ALMA Early Science Cycle0 is coming soon with unprecedented sensitivity. Prepare for your proposal with understanding ALMA Cycle0 capability. Cycle0 final spec will be decided by Mid March. Join us in the ALMA special session on Mar 16 th in the ASJ annual meeting in Tsukuba. EA PS Report 2nd ALMA Users Meeting 2011/1/13 20

2nd ALMA Users Meeting 2011/1/ 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.. EA PS Report