* Astronomy

Blobrana · L

RE: Nobeyama observatory

Blobrana · L

The Nobeyama Radio Observatory (NRO) is a division of the National Astronomical Observatory of Japan (NAOJ) under the National Institutes of Natural Sciences (NINS). NRO operates powerful, advanced radio telescopes such as the 45 m radio telescope, the Nobeyama Millimeter Array (NMA), and the Nobeyama Radioheliograph. A large number of scientists from around the world visit NRO to use these telescopes for researches in astronomy and astrophysics. Maintenance, upgrades, and new technical innovations are ceaselessly made all year round.

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Blobrana · L

Title: New 60-cm Radio Survey Telescope with the Sideband-Separating SIS Receiver for the 200 GHz Band
Authors: Taku Nakajima, Masahiro Kaiden, Jun Korogi, Kimihiro Kimura, Yoshinori Yonekura, Hideo Ogawa, Shingo Nishiura, Kazuhito Dobashi, Toshihiro Handa, Kotaro Kohno, Jun-Ichi Morino, Shin'ichiro Asayama, Takashi Noguchi

We have upgraded the 60-cm radio survey telescope located in Nobeyama, Japan. We developed a new waveguide-type sideband-separating SIS mixer for the telescope, which enables the simultaneous detection of distinct molecular emission lines both in the upper and lower sidebands. Over the RF frequency range of 205-240 GHz, the single-sideband receiver noise temperatures of the new mixer are 40-100 K for the 4.0-8.0 GHz IF frequency band. The image rejection ratios are greater than 10 dB over the same range. For the dual IF signals obtained by the receiver, we have developed two sets of acousto-optical spectrometers and a telescope control system. Using the new telescope system, we successfully detected the 12CO (J=2-1) and 13CO (J=2-1) emission lines simultaneously toward Orion KL in 2005 March. Using the waveguide-type sideband-separating SIS mixer for the 200 GHz band, we have initiated the first simultaneous 12CO (J=2-1) and 13CO (J=2-1) survey of the galactic plane as well as large-scale mapping observations of nearby molecular clouds.

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