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. Keep in mind that currently OTF maps cannot be oriented along custom position angles, and are always aligned with the North-South direction.
  • 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: 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

    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.