ALMA Cycle 2 Capability
Jongsoo Kim
ALMA EA Korea node
Locations of ALMA and GMT
ALMA
GMT
Antennas
50x12m-Array + 12x7mArray + 4 12m-TP Array
Longest baseline: 16 km
Current: 66 delivered
Completed in 2013(?)
Resolution and Sensitivity Comparison
ALMA
Atacama 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
MRS
1 .2 
2

CAR 
2Lmin
166 m
FAR 

1 .5 km (1.0 km)
7-m Array Configuration, TP
Low elevation
7-m
TP
62
41
27
18
13
HFBW


12 m
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 (C341,2,3)
• 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
restriction
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
partnership 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 National
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.
Large Mass Loss
from R Sculptoris,
an AGB Star
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
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