Toyama Microwave Atlas for spectroscopists and astronomers

Department of Physics, University of Toyama has a long standing tradition of microwave spectroscopy of molecules with internal rotors since Professor Takeshi Kojima started microwave spectroscopy. Microwave transitions of these molecules are observed all over the frequency range and often hard to analyze all spectral lines. Some of these molecules are also identified in the interstellar medium. For spectroscopic and astronomical purpose, it was desirable to have the entire laboratory frequency list whether the lines are assigned or not. Toyama Microwave Atlas of most known interstellar molecule CH3OH was thus first prepared in 1995 as two books; each one shows the frequency list and the observed spectra. The frequency range was 8 - 200 GHz. Since that time atlas of acetamide (CH3CONH2), methyl formate (HCOOCH3), and t-ethyl methyl ether (CH3CH2OCH3) were added in 2001, 2004, and 2004, respectively. These books, however, are often hard to access. Update was also a problem. Thus we started a project to prepare searchable online form of these book Atlases. We plan to keep updating our data and also ask for collaborations from many researchers.

The new telescope, ALMA, currently under construction in Chile has higher sensitivity, and many weaker lines will be observed very soon. Part of the origin would be found to be due to such a large organic molecules in this Atlas. The results would help to understand the temperature, abundance, and chemical reactions there. We hope this Atlas are of use for both spectroscopists and astronomers. Please refer our database as Toyama Microwave Atlas.

Researchers involved (affiliations)
Kaori Kobayashi (University of Toyama), Shozo Tsunekawa (University of Toyama), Fusakazu Matsushima (University of Toyama), Satoshi Yamamoto (University of Tokyo), Masatoshi Ohishi (National Astronomical Observatory of Japan (NAOJ))

Contributors of book atlases (Toyama University)
Kojiro Takagi, Hitoshi Odashima, Tomomi Ukai (CH3OH), Kazuhiko Oka (HCOOCH3) and many graduate and undergraduate students.

Contributors of Atlas Web page
Takeshi Kurimoto (University of Toyama)

List of Molecules
Information about quantum numbers for each molecule is also included in this list of molecules.

Atlas Search

Experimental condition


Future plan

In the University of Toyama, researches of laboratory spectroscopy of organic molecules have been continued. This homepage will be updated in the future and we will be glad your comments.

Interested in Contribution?

Contact Kaori Kobayashi. We are looking forward to your participation.


This atlas project has been supported by the following fundings, National Radio Observatory, a Grant-in- Aid from the Ministry of Education, Science, Sports and Culture of Japan, and University of Toyama.
The book atlases were partly supported by a Grant-in- Aid from the Ministry of Education, Science, Sports and Culture of Japan.


  • Microwave Laboratory, Department of Physics, University of Toyama


      Kaori Kobayashi (Department of Physics, University of Toyama) (replace -at- with @)
      Tel. +81-76-445-6595

      Last update, Jun. 6th, 2014