YEBES OBSERVATORY
A Spanish Scientific and Technical Infrastructure

40m RT basic technical information

Observing modes

Spectral observations. These observations are available under several standard modes: position switching, frequency switching, Wobbler Switching, and On-The-Fly (OTF) position-switch mapping (IMPORTANT: 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.

Important Notes:

  • Wobbler Switching is offered in shared-risk mode, with offset throws ranging from ±160 to ±400 arcsec, and wobbling frequencies ranging from 0.0625 and 0.25 Hz.
  • On-the-fly spectral mapping in the Q and W bands is available with the full bandwidth of 18.5 GHz.
  • 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.
  • The tri-band (K/Q/W) dual polarization VLBI mode with DBBC3 backends is currently NOT being offered. Only DBBC2, single-band VLBI observations are offered for the time being.
  • 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

Available observing frequencies:

  • C band: 4.9 - 5.4 GHz & 6.1 - 6.6 GHz (currently Single-Dish Director Discretionary Time or VLBI only)
  • X Band: 8.1 - 8.9 GHz (currently Single-Dish Director Discretionary Time or VLBI only)
  • K Band: 21 - 25 GHz (currently VLBI only)
  • Q Band: 31.3 - 50.6 GHz (for technical details see Tercero et al, 2021)
  • W Band: 72 - 90 GHz (for technical details see Tercero et al, 2021)

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: 8 GHz (low - 18-26 GHz) and 6 GHz (high - 26-32 GHz). Spectral resolution: 15 kHz.
    Freq (GHz) λ (mm) θHPBW (´´) Polarization ηA ηMB Jy/K
    22.3 13.5 79.1 H 0.60 0.69 3.40
    V 0.59 0.69 3.45
  • Q Band. Bandwidth: 18.5 GHz. Spectral resolution: 38 kHz

    Click on the buttons inside the tabbed menu to display the angular resolution and efficiencies:

    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

    • 2021

    No data taken.

    Freq (GHz) λ (mm) θHPBW (´´) Polarization ηA ηMB Jy/K
    32.4 9.3 54.4 H 0.57 0.66 3.54
    V 0.56 0.65 3.60
    34.5 8.7 51.1 H 0.54 0.62 3.78
    V 0.53 0.62 3.78
    36.9 8.1 47.8 H 0.53 0.62 3.79
    V 0.52 0.60 3.87
    39.2 7.7 45.0 H 0.51 0.59 3.97
    V 0.50 0.58 4.02
    41.5 7.2 42.5 H 0.50 0.58 4.04
    V 0.49 0.56 4.14
    43.7 6.9 40.4 H 0.48 0.56 4.17
    V 0.47 0.54 4.31
    46.0 6.5 38.3 H 0.47 0.54 4.34
    V 0.44 0.51 4.58
    48.4 6.2 36.4 H 0.44 0.51 4.57
    V 0.42 0.49 4.82

    2021

    No data taken.

    Freq (GHz) λ (mm) θHPBW (´´) Polarization ηA ηMB Jy/K
    32.4 9.3 54.4 H 0.56 0.65 3.73
    V 0.55 0.64 3.78
    34.6 8.7 51.0 H 0.53 0.61 3.96
    V 0.53 0.61 3.94
    36.9 8.1 47.8 H 0.53 0.61 3.95
    V 0.52 0.60 4.01
    39.2 7.7 45.0 H 0.51 0.59 4.10
    V 0.50 0.58 4.15
    41.5 7.2 42.5 H 0.50 0.58 4.16
    V 0.49 0.57 4.23
    43.8 6.8 40.3 H 0.48 0.56 4.34
    V 0.48 0.55 4.38
    46.1 6.5 38.3 H 0.47 0.54 4.48
    V 0.46 0.54 4.50
    48.4 6.2 36.4 H 0.45 0.52 4.63
    V 0.44 0.51 4.73

  • W Band. Bandwidth: 18.5 GHz. Spectral resolution: 38 kHz

    Click on the buttons inside the tabbed menu to display the angular resolution and efficiencies:

    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

    • 2021

    No data taken.

    Freq (GHz) λ (mm) θHPBW (´´) Polarization ηA ηMB Jy/K
    72.5 4.1 24.3 H 0.26 0.30 7.38
    V 0.26 0.31 7.32
    74.7 4.0 23.6 H 0.25 0.29 7.73
    V 0.25 0.29 7.67
    77.0 3.9 22.9 H 0.24 0.28 7.95
    V 0.24 0.28 8.02
    79.3 3.8 22.2 H 0.23 0.27 8.40
    V 0.23 0.27 8.44
    81.6 3.7 21.6 H 0.22 0.25 8.82
    V 0.22 0.25 8.91
    83.9 3.6 21.0 H 0.21 0.24 9.25
    V 0.21 0.24 9.34
    86.2 3.5 20.5 H 0.20 0.23 9.76
    V 0.19 0.22 9.96
    88.5 3.4 19.9 H 0.19 0.22 10.12
    V 0.18 0.21 10.50

    2021

    No data taken.

    Freq (GHz) λ (mm) θHPBW (´´) Polarization ηA ηMB Jy/K
    72.5 4.1 24.3 H 0.33 0.38 6.19
    V 0.32 0.37 6.38
    74.7 4.0 23.6 H 0.32 0.37 6.40
    V 0.31 0.36 6.59
    77.0 3.9 22.9 H 0.31 0.36 6.56
    V 0.30 0.34 6.85
    79.3 3.8 22.2 H 0.29 0.34 6.92
    V 0.28 0.33 7.11
    81.6 3.7 21.6 H 0.28 0.32 7.22
    V 0.27 0.32 7.40
    83.9 3.6 21.0 H 0.27 0.31 7.54
    V 0.26 0.30 7.83
    86.2 3.5 20.5 H 0.26 0.30 7.81
    V 0.25 0.28 8.16
    88.5 3.4 19.9 H 0.25 0.29 8.09
    V 0.23 0.27 8.58

The 18.5 GHz expansion of bands Q and W has been supported by project Nanocosmos (ERC-2013-Syg-610256-NANOCOSMOS) during 2019.