45m望遠鏡の装置情報

This status report summarises the instrumental status of the Nobeyema 45-m radio telescope such as an antenna, receivers, and backends.

Important Notice

The continuum mode for science target observation is not offered in open use. The continuum mode is only available for pointing observations.

Nobeyama 45-m Telescope is one of the largest millimetre radio telescopes in the world.
The 45-m Telescope covers a frequency range of 20 – 116 GHz with several receivers.
Mirrors in optics part are used for the receiver selection.
Output signals from a receiver (IF signals) are processed in the IF chains, and fed to backends.
There are two backends, one is “SAM45” for spectroscopic observations, and the other is “Continuum BE” for continuum observations.

(*1) Beam squint of H22 respect to H40 is ∼4 arcsec., which is small enough compared to the beam size of H22 (∼72 arcsec.) for most of the observations.
(*2) Beam squint of H22 respect to Z40 is ∼2 arcsec. (see acceptance report material for detail), which is small enough compared to the beam size of H22 (∼72 arcsec.) for most of the observations.
(*3) For observatiosn of 72 GHz band, FOREST can be used, but the optimal tuning parameters are not searched completely. Typical Tsys are (72 GHz) 300 K, (80 – 110 GHz) 150 K, and (115 GHz) 300 K.
(*4) From the limitation of the number of backend (16), two IFs of four have to be choiced.

Notes: The errors of the efficiencies are mainly due to the uncertainty of brightness temperature of the planets.

(*) Based on the relative measurements between normal and filter modes.

Users are recommended to avoid to observe targets located within 30 degrees from the Sun because the thermal deformation of the antenna degrades the efficiencies.
Users who would like to observe the Sun or targets near the Sun should take care of them.
Additional information is available here.

Typical accuracy of ∼3 arcsec (rms) will be achieved by
- five-point cross observations of a SiO maser (spectroscopy observations)
- or
- cross scan observations of planets (continuum observations)
List of pointing sources:
- SiO maser: web page, CSV file
- Continuum: CSV file; Please check the recent flux of source. (e.g., Submillimeter Calibrator List @ SMA)
It is appropriate to conduct a pointing measurement and correction every 1 – 1.5 hours.
- It is appropriate to conduct a pointing measurement and correction every 30 minutes during the sunrise and sunset when the outside temperature changes drastically.
The pointing accuracy above is achievable for wind speed of less than 4 m/s. It can be degraded if wind velocity exceeds 10 m/s.
Users are recommended to avoid to observing targets located within 30 degrees from the Sun because the thermal deformation of the antenna degrades the pointing accuracy.
Users who would like to observe the Sun or targets near the Sun should take care of them.
For the simultaneous observations with H22 and H40 receivers:
- Pointing measurements should be done with H40 receiver.
- Please note that the beam squint of H22 respect to H40 is ∼4 arcsec., which is small enough compared to the beam size of H22 (∼72 arcsec.) for most of the observations.

Please see Remote Observation
- from Mitaka Campus, National Astronomical Observatory of Japan
- from Your Home Institute in Japan
- from Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan
- from Korea Astronomy and Space Science Institute (KASI) in Korea