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40m RT basic technical information
Observing modes
Spectral observations. These observations are available under several standard modes: position switching, frequency switching and On-The-Fly (OTF) position-switch mapping (see below). Position Switch observations can be programmed ad-hoc using several phases. The spectral backends are Fast Fourier Spectrometers (FFTs) with 100 MHz, 500 MHz, 1.5 GHz and 2.5 GHz bandwidths with 6 KHz, 30 KHz, 180 KHz and 38 KHz resolution respectively.
Continuum observations. These observations are restricted to total power pointing drifts or focus drifts. Position switch using a wobbler or a beam switch are not available. Currently there are several backends offering a bandwidth of 2.5 GHz, 1.5 GHz, 500 MHz or 100 MHz depending on the observed frequency.
Important Notes:
- Keep in mind that there is usually a strong demand for objects in the region between 2:00 and 9:00 LST. Depending on the proposal ranking, Requesting sources in this LST range could therefore find it harder for observations to be carried out
- W band (72 - 90 GHz) observations are available for a limited number of hours in the semester (night time only, from 2 hours after sunset to sunrise, due to thermal distortion in the telescope structure), with a bandwidth of 18.5 GHz.
- On-the-fly spectral mapping in the Q and W bands is available with the full bandwidth of 18.5 GHz.
Available observing frequencies:
- C band: 4.9 - 5.4 GHz & 6.1 - 6.6 GHz (currently VLBI only)
- X Band: 8.1 - 8.9 GHz (currently VLBI only)
- K Band: 21 - 25 GHz (currently Single-Dish Director Discretionary Time observations or VLBI only)
- Q Band: 31.3 - 50.6 GHz
- W Band: 72 - 90 GHz
Instantaneous bandwidth, spectral resolution, angular resolution, aperture efficiency, main beam efficiency and Jy/K conversion
- C Band. Bandwidth: 500 MHz. Spectral resolution: 6.1 & 30 KHz. θb=260’’, ηA=0.46
- X Band. Bandwidth: 500 MHz. Spectral resolution: 6.1 & 30 KHz. θb=180’’, ηA=0.70
- K Band. Bandwidth: 500 MHz. Spectral resolution: 6.1 & 30 KHz
| Freq (GHz) |
λ (mm) |
θHPBW (´´) |
Polarization |
ηA |
ηMB |
Jy/K |
| 22.3 |
13.5 |
79.1 |
R |
0.60 |
0.69 |
3.40 |
| L |
0.59 |
0.69 |
3.45 |
- Q Band. Bandwidth: 18.5 GHz. Spectral resolution: 38 KHz. ηf = 0.97
| Freq (GHz) |
λ (mm) |
θHPBW (´´) |
Polarization |
ηA |
ηMB |
Jy/K |
| 32.4 |
9.3 |
54.4 |
H |
0.53 |
0.61 |
3.83 |
| V |
0.52 |
0.61 |
3.86 |
| 34.6 |
8.7 |
51.0 |
H |
0.50 |
0.58 |
4.07 |
| V |
0.50 |
0.58 |
4.05 |
| 36.9 |
8.1 |
47.8 |
H |
0.49 |
0.57 |
4.11 |
| V |
0.49 |
0.56 |
4.16 |
| 39.2 |
7.7 |
45.0 |
H |
0.47 |
0.55 |
4.29 |
| V |
0.47 |
0.55 |
4.29 |
| 41.5 |
7.2 |
42.5 |
H |
0.46 |
0.53 |
4.39 |
| V |
0.46 |
0.53 |
4.39 |
| 43.8 |
6.8 |
40.3 |
H |
0.44 |
0.51 |
4.55 |
| V |
0.45 |
0.52 |
4.54 |
| 46.1 |
6.5 |
38.3 |
H |
0.42 |
0.49 |
4.78 |
| V |
0.43 |
0.49 |
4.74 |
| 48.4 |
6.2 |
36.4 |
H |
0.41 |
0.47 |
4.95 |
| V |
0.41 |
0.47 |
4.94 |
- W Band. Bandwidth: 18.5 GHz. Spectral resolution: 38 KHz
| Freq (GHz) |
λ (mm) |
θHPBW (´´) |
Polarization |
ηA |
ηMB |
Jy/K |
| 72.5 |
4.1 |
24.3 |
H |
0.30 |
0.35 |
6.50 |
| V |
0.31 |
0.36 |
6.35 |
| 74.7 |
4.0 |
23.6 |
H |
0.28 |
0.33 |
6.91 |
| V |
0.30 |
0.34 |
6.65 |
| 77.0 |
3.9 |
22.9 |
H |
0.27 |
0.31 |
7.35 |
| V |
0.28 |
0.32 |
7.14 |
| 79.3 |
3.8 |
22.2 |
H |
0.26 |
0.30 |
7.72 |
| V |
0.26 |
0.30 |
7.51 |
| 81.6 |
3.7 |
21.6 |
H |
0.24 |
0.28 |
8.17 |
| V |
0.25 |
0.29 |
8.00 |
| 83.9 |
3.6 |
21.0 |
H |
0.23 |
0.27 |
8.48 |
| V |
0.23 |
0.26 |
8.75 |
| 86.2 |
3.5 |
20.5 |
H |
0.22 |
0.26 |
8.94 |
| V |
0.20 |
0.23 |
9.88 |
| 88.5 |
3.4 |
19.9 |
H |
0.22 |
0.26 |
8.70 |
| V |
0.19 |
0.21 |
10.68 |
The 18.5 GHz expansion of bands Q and W has been supported by project Nanocosmos (ERC-2013-Syg-610256-NANOCOSMOS) during 2019.
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