ALMA Cycle 2 Capability

Jongsoo Kim

ALMA EA Korea node

Locations of ALMA and GMT

ALMA

GMT

Antennas50x12m-Array + 12x7m-Array + 4 12m-TP Array

Longest baseline: 16 km

Current: 66 delivered

Completed in 2013(?)

Resolution and Sensitivity Comparison

ALMAAtacama Large Millimeter/Submillimeter Array

C2: Antennas

• 34 12m-Array• ACA Array: complement to 12m-Array

– 9 7m-Array• Shorter baselines• No WVR (Water Vapor Radiometer)

– 2 12-m TP Array• Single dish observations• Spectral line (no continuum) observations in Band 3-8

(no 9)

Atmospheric Transparency

C2: Receivers

• B2,4,6,7: 1.5km, B8,9: 1km• B2,4,6,7,8,9: dual pol, XX,YY

7-m, 12-m Array Configurations

7 configurations Most compact confi. with

max baseline 160m Most extended conf. with

max baselines,

1.5km for B3,4,6,7,

1.0km for B8,9

12-m Array configurations

min22.1LMRS

mCAR 166

2 km) (1.0 km 5.1

FAR

7-m Array Configuration, TPLow elevation

mHFBW 12

62

41

18

13

27

7-m TP

Time Estimates for mult-conf.

• Rule of thumb– estimate dt_ex, for 12-m extended configuration

(C34-4,5,6,7)– 4*dt_ex for TP– 2*dt_ex for 7-m Array– 0.5*dt_ex for 12-m compact configuration (C34-

1,2,3)

• Use OT• Total time (12-m+ACA) < 100 hours

Spectral Capability

Number of BBs in 2SB in each sideband: 0, 1, 2, 4

Number of BBs in DSB (B9): no restric-tion

Spw in each BB: up to 4, share correlator resource among them

Should have same correlator mode with a BB

Binning of data of power 2 mainly due to limitation of data rate, maximum 60MB/s, average 6MB/s

Correlator mode

Polarization

• Single Polarization, XX: more bandwidth or more spectral resolution

• Dual Polarization XX, YY: improve sensitivity of sqrt(2) compared with single pol case

• Full polarization XX, XY, YX, YY:– continuum obs in Band 3,6,7– LAS < 1/3 12-m primary beam, single field– Fixed frequencies

Source restrictions

• “SG(Science Goal): single angular resolution, sensitivity, LAS, receiver band

• No restriction on number of SG per proposal• Total # of positions with 10 deg < 150 per SG

per array• One mosaic observing mode < 150 positions

per SG

Calibration

• Absolute Amplitude calibration– Better than 5% in B 3,4– Better than 10% in B 6,7– Better than 20% in B 8,9 due to high opacity and

DSB of B9

ToO

• Only 12-m array• < 2 weeks monitoring projects are unlikely

fully observed• within 2 weeks contact can not be guaranteed

ALMA Partnership

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partner-ship of 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 Na-tional Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

Maercker+ 2012 (Oct-11), Nature

Cyclo 0

December 2011, data delivered

CO(J=3- 2) 345GHz

1.3’’x10’’ beam

50’’x50’’ map, 45-point mosaic

CASA

Large Mass Loss from R Sculptoris, an AGB Star

ALMA survey of SMGs in ECDFS (Extended Chandra Deep Field South)

Hodge+ 2013, ApJ, Cycle 0

ALMA band 7 (344GHz, 870mm)

Primary beam: 17.3 arcsec

Angular resolution: 1.5 arcsec (125m)

Observed 126 subm sources detected in LESS (LABOCA ECDFS Submillimeter Survey) by 12m APEX

2 minutes integration time for each source

3x sensitivity 200x resolution

Resolve previously blended sources Main 99 SMGs+ supplementary 32

SMGs