CCAT Sensitivities

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CCAT Sensitivities

• Last Update 12-May-05

TLH
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Table 1 CCAT Baseline Sensitivity
? n PWV NEFD Conf. Limit Time to CL Density at CL
(?m) (GHz) (mm) (mJy) (mJy) (sec) (/sq-deg)
200 1500 0.3 150.96 0.356   115935
228 1317 0.3 116.67 0.529   89409
291 1030 0.3 114.17 0.926   54677
350 857 0.4 14.41 1.293 3106 37856
450 667 0.5 13.80 1.450 2262 22901
620 484 0.5 16.35 1.277 4100 12064
740 405 0.7 8.74 1.112 1545 8469
865 347 1.0 5.83 0.922 998 6198
1103 273 1.0 2.06 0.670 236 3833
1181 254 1.0 1.74 0.610 204 3325
1400 214 1.5 2.93 0.447 1072 2366
2000 150 1.5 2.30 0.196 3458 1159
3300 90.9 1.5 2.82 0.080 30773 426
Sensitivity selected on the basis of appropriate
PWV for that wavelength. NEFD is 1-sigma in 1
second. Confusion limit (CL) is for 30
beams/source. Time to CL is for S/N 5. Source
density is for all sources ? CL flux.
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Table 2 CCAT Sensitivity vs. PWV
  NEFD (mJy) - 1-sigma, 1-second NEFD (mJy) - 1-sigma, 1-second NEFD (mJy) - 1-sigma, 1-second NEFD (mJy) - 1-sigma, 1-second NEFD (mJy) - 1-sigma, 1-second NEFD (mJy) - 1-sigma, 1-second NEFD (mJy) - 1-sigma, 1-second NEFD (mJy) - 1-sigma, 1-second
(mm) n(GHz) 0.125 0.25 0.30 0.40 0.50 0.70 1.00 2.00
200 1500 48.45 111.10 150.96 272.50 483.17 1481.21  
228 1317 32.78 82.86 116.67 225.86 429.39 1516.22  
291 1030 34.24 82.86 114.17 210.79 380.75 1205.74    
350 857 7.54 10.36 11.63 14.41 17.59 25.32 41.45 175.66
450 667 5.98 8.24 9.23 11.39 13.80 19.51 30.89 113.70
620 484 5.32 8.34 9.71 12.78 16.35 25.32 44.99 234.54
740 405 4.28 5.17 5.54 6.30 7.08 8.74 11.46 23.07
865 347 2.90 3.29 3.45 3.77 4.10 4.77 5.83 9.82
1103 273 1.33 1.43 1.47 1.56 1.64 1.80 2.06 2.95
1181 254 1.09 1.18 1.22 1.29 1.37 1.52 1.74 2.55
1400 214 1.72 1.82 1.87 1.95 2.04 2.21 2.48 3.39
2000 150 1.48 1.55 1.58 1.64 1.70 1.82 2.00 2.62
3300 90.9 1.77 1.87 1.90 1.98 2.05 2.20 2.43 3.22
Bold numbers are the baseline sensitivity for
CCAT. Assumptions 30 deg from zenith, 12 mm
surface rms, chopping/difference loss of 1.414,
5000m altitude for transmission calculations (but
consistent with tau(222 mm) measurements from
Sairecabur). PWV varies from 0.125 to 2.0 mm.
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Table 3 CCAT Confusion Limits
Flux (mJy) Flux (mJy)
lam(um) 10 beam/src 30 beams/src
200 0.042 0.356
250 0.103 0.529
350 0.242 0.926
450 0.372 1.293
651 0.530 1.450
741 0.559 1.277
872 0.529 1.112
1099 0.461 0.922
1400 0.359 0.670
2100 0.329 0.610
3300 0.248 0.447
From Andrew Blain, 3/28/05. Updated to be
consistent with beam size definition used in
sensitivity calculation.
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Figure 1 CCAT Sensitivity
Confusion limits for Spitzer, Herschel, APEX,
JCMT, and LMT are shown.
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Figure 2 CCAT Sensitivity
Confusion limits for Spitzer, Herschel, APEX,
JCMT, and LMT are shown.
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Figure 3 Mapping Speed
Table 4 Table 4
Speed Advantage CCAT/ALMA Speed Advantage CCAT/ALMA
l (mm) SpeedGain
350 1760
450 510
860 32
1300 48
2100 20
3300 12
Mapping speed (Field-of-viewNEFD-2) of CCAT vs.
ALMA. Assumes 12-m dish for ALMA and 150x150
array sampled at 2-pixels/resolution element for
a 25-m CCAT. The table at right represents the
speed gain for CCAT over ALMA (ratio of the
mapping speeds).
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Figure 4 NEFD vs. PWV
Changing in CCAT sensitivity vs. precipitable
water vapor for different operating wavelengths.
NEFD is the flux density for 1-sigma in 1
second.
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Figure 5 Performance vs. Surface RMS
Changing in CCAT sensitivity vs. total rms
surface accuracy for different operating
wavelengths. NEFD is the flux density for
1-sigma in 1 second.
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Figure 6 Atmospheric Transmission
Atmospheric transmission for different amounts of
precipitable water vapor. The horizontal red
bars represent the adopted bandpasses and the
average transmission for 0.25 mm PWV.
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Table 4 CCAT Line Sensitivity
lam Freq PWV NEFD Line Flux
(mm) (GHz) (mm) (mJy) (W/m2)
200 1500 0.3 1627.0 2.44E-17
228 1317 0.3 1760.3 2.32E-17
291 1030 0.3 1182.5 1.22E-17
350 857 0.4 253.4 2.17E-18
450 667 0.5 231.7 1.54E-18
620 484 0.5 272.4 1.32E-18
740 406 0.7 111.1 4.50E-19
865 347 1.0 91.1 3.16E-19
1103 272 1.0 61.4 1.67E-19
1181 254 1.0 62.1 1.58E-19
1400 214 1.5 62.3 1.33E-19
2000 150 1.5 58.4 8.34E-20
3300 91 1.5 64.6 5.87E-20
R 1000 spectroscopic sensitivity for CCAT.
Numbers are for 1-sigma in 1-second. Sensitivity
selected on the basis of appropriate PWV for that
wavelength. Note these numbers are for a
non-heterodyne spectrograph.