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 The Committee on Radio Astronomy Frequencies (CRAF) is a committee of the European Science Foundation (ESF).


Radio frequencies of the astrophysically most important spectral lines


1. IAU list of important spectral lines

At the XXIst General Assembly of the International Astronomical Union, IAU, (Buenos Aires, July 23 - August 1, 1991) the astrophysically most important spectral lines have been carefully reviewed. The IAU listed the revision of these spectral lines as reproduced below. The IAU expressed the need to protect these frequency bands from in-band, band-edge and harmonic emissions, especially from space-borne transmitters.

 
 
Substance                            Rest           Suggested        Notes1) 
                                  Frequency      minimum bandwidth 
 
Deuterium (DI)                     327.384 MHz    327.0 -  327.7  MHz 
Hydrogen (HI)                     1420.406 MHz   1370.0 - 1427.0  MHz   2),3) 
Hydroxyl radical (OH)             1612.231 MHz   1606.8 - 1613.8  MHz   3),4) 
Hydroxyl radical (OH)             1665.402 MHz   1659.8 - 1667.1  MHz   4) 
Hydroxyl radical (OH)             1667.359 MHz   1661.8 - 1669.0  MHz   4) 
Hydroxyl radical (OH)             1720.530 MHz   1714.8 - 1722.2  MHz   3),4) 
Methyladyne (CH)                  3263.794 MHz   3252.9 - 3267.1  MHz   3),4) 
Methyladyne (CH)                  3335.481 MHz   3324.4 - 3338.8  MHz   3),4) 
Methyladyne (CH)                  3349.193 MHz   3338.0 - 3352.5  MHz   3),4) 
Formaldehyde (H2CO)               4829.660 MHz   4813.6 - 4834.5  MHz   3),4) 
Methanol (CH2OH)                  6668.518 MHz   6661.8 - 6675.2  MHz   3),6) 
Ionized Helium Isotope (3HeII)    8665.650 MHz   8660.0 - 8670.0  MHz 
Methanol (CH3OH)                    12.178 GHz     12.17-   12.19 GHz   3),6) 
Formaldehyde (H2CO)                 14.488 GHz     14.44-   14.50 GHz   3),4) 
Cyclopropenylidene (C3H2)           18.343 GHz     18.28-   18.36 GHz   3),4),6)
Water Vapour (H2O)                  22.235 GHz     22.16-   22.26 GHz   3),4) 
Ammonia (NH3)                       23.694 GHz     23.61-   23.71 GHz   4) 
Ammonia (NH3)                       23.723 GHz     23.64-   23.74 GHz   4) 
Ammonia (NH3)                       23.870 GHz     23.79-   23.89 GHz   4) 
Silicon monoxide (SiO)              42.519 GHz     42.47-   42.57 GHz   3)
Silicon monoxide (SiO)              42.821 GHz     42.77-   42.86 GHz 
Silicon monoxide (SiO)              42.880 GHz     42.83-   42.93 GHz
Silicon monoxide (SiO)              43.122 GHz     43.07-   43.17 GHz 
Silicon monoxide (SiO)              43.424 GHz     43.37-   43.47 GHz  
Carbon monosulphide (CS)            48.991 GHz     48.94-   49.04 GHz 
Deuterated formylium (DCO+)         72.039 GHz     71.96-   72.11 GHz   3) 
Silicon monoxide (SiO)              86.243 GHz     86.16-   86.33 GHz 
Formylium (H13CO+)                   86.754 GHz     86.66-   86.84 GHz 
Silicon monoxide (SiO)              86.847 GHz     86.76-   86.93 GHz 
Ethynyl radical (C2H)               87.300 GHz     87.21-   87.39 GHz   5) 
Hydrogen cyanide (HCN)              88.632 GHz     88.34-   88.72 GHz   4) 
Formylium (HCO+)                    89.189 GHz     88.89-   89.28 GHz   4) 
Hydrogen isocyanide (HNC)           90.664 GHz     90.57-   90.76 GHz 
Diazenylium (N2H)                   93.174 GHz     93.07-   93.27 GHz 
Carbon monosulphide (CS)            97.981 GHz     97.65-   98.08 GHz   4) 
Carbon monoxide (C18O)             109.782 GHz    109.67-  109.89 GHz 
Carbon monoxide (13CO)             110.201 GHz    109.83-  110.31 GHz   4) 
Carbon monoxide (C17O)             112.359 GHz    112.25-  112.47 GHz   6) 
Carbon monoxide (CO)               115.271 GHz    114.88-  115.39 GHz   4) 
Formaldehyde (H213CO)               137.450 GHz    137.31-  137.59 GHz   3),6) 
Formaldehyde (H2CO)                140.840 GHz    140.69-  140.98 GHz 
Carbon monosulphide (CS)           146.969 GHz    146.82-  147.12 GHz 
Water vapour (H2O)                 183.310 GHz    183.12-  183.50 GHz 
Carbon monoxide (C18O)             219.560 GHz    219.34-  219.78 GHz 
Carbon monoxide (13CO)             220.399 GHz    219.67-  220.62 GHz   4) 
Carbon monoxide (CO)               230.538 GHz    229.77-  230.77 GHz   4) 
Carbon monosulphide (CS)           244.953 GHz    244.72-  245.20 GHz   6) 
Hydrogen cyanide (HCN)             265.886 GHz    265.62-  266.15 GHz 
Formylium (HCO+)                   267.557 GHz    267.29-  267.83 GHz 
Hydrogen isocyanide (HNC)          271.981 GHz    271.71-  272.25 GHz 
Dyazenulium (N2H+)                 279.511 GHz    279.23-  279.79 GHz 
Carbon monoxide (C18O)             312.330 GHz    329.00-  329.66 GHz 
Carbon monoxide (13CO)             330.587 GHz    330.25-  330.92 GHz 
Carbon monosulphide (CS)           342.883 GHz    342.54-  343.23 GHz 
Carbon monoxide (CO)               345.796 GHz    345.45-  346.14 GHz 
Hydrogen cyanide (HCN)             354.484 GHz    354.13-  354.84 GHz 
Formylium (HCO+)                   356.734 GHz    356.37-  357.09 GHz 
Dyazenulium (N2H+)                 372.672 GHz    372.30-  373.05 GHz 
Water vapour (H2O)                 380.197 GHz    379.81-  380.58 GHz 
Carbon monoxide (C18O)             439.088 GHz    438.64-  439.53 GHz 
Carbon monoxide (13CO)             440.765 GHz    440.32-  441.21 GHz 
Carbon monoxide (CO)               461.041 GHz    460.57-  461.51 GHz 
Heavy water (HDO)                  464.925 GHz    464.46-  465.39 GHz 
Carbon (CI)                        492.162 GHz    491.66-  492.66 GHz 
Water vapour (H218O)               547.676 GHz    547.13-  548.22 GHz 
Water vapour (H2O)                 556.936 GHz    556.37-  557.50 GHz 
Ammonia (15NH3)                    572.113 GHz    571.54-  572.69 GHz 
Ammonia (NH3)                      572.498 GHz    571.92-  573.07 GHz 
Carbon monoxide (CO)               691.473 GHz    690.78-  692.17 GHz 
Hydrogen cyanide (HCN)             797.433 GHz    796.64-  789.23 GHz 
Formylium (HCO+)                   802.653 GHz    801.85-  803.85 GHz 
Carbon monoxide (CO)               806.652 GHz    805.85-  807.46 GHz 
Carbon (CI)                        809.350 GHz    808.54-  810.16 GHz 
 
 
1): If Note 4) or Note 2) are not listed, the 
    band limits are Doppler-shifted frequencies corresponding to radial 
    velocities of +/- 300 km/s (consistent with line radiation occurring in 
    our galaxy). 
 
2): An extension to lower frequencies of the allocation of 1400-1427 MHz 
    is required to allow for the Doppler shifts for HI observed in distant 
    galaxies. 
 
3): The current international allocation is not primary and/or does 
    not meet bandwidth requirements. See: ITU-R Radio Regulations (Table 8) 
    for more detailed information. 
 
4): Because these line frequencies are also being used for observing 
    other galaxies, the listed bandwidths include Doppler shifts 
    corresponding to radial velocities of up to 1000 km/s. It should be noted 
    that HI has been observed at frequencies redshifted to 500 MHz, while 
    some lines of the most abundant molecules have been detected in galaxies 
    with velocities up to 50 000 km/s, corresponding to a frequency reduction 
    of up to 17%. 

5): There are six closely spaced lines associated with this molecule 
    at this frequency. The listed band is wide enough to permit observations 
    of all six lines. 
 
6): This line is not mentioned in Article 8 of the ITU-R Radio 
    Regulations. 


2. Supplementary list of important spectral lines of the IUCAF mm-wave working group

In preparation of the World Radiocommunication Conference 2000, WRC-2000, which revised the allocations above 71 GHz, the IUCAF mm-wavelength working group has examined all known transitions in the millimeter and submillimeter wavebands. They have selected a limited number of the astrophysically most important spectral lines. This list supplements earlier lists such as those produced by the International Astronomical Union, IAU, (see above) and is to be used in allocating frequency bands to the Radio Astronomy Service.

 
Substance                                   Rest                  Suggested 
                                         Frequency            minimum bandwidth 

Deuterium (DI)                           327.348 MHz        327.0  -     327.7  MHz  
Hydrogen (HI)                           1420.406 MHz       1370.0  -    1427.0  MHz  
Hydroxyl radical (OH)                   1612.231 MHz       1606.8  -    1613.8  MHz  
Hydroxyl radical (OH)                   1665.402 MHz       1659.8  -    1667.1  MHz  
Hydroxyl radical (OH)                   1667.359 MHz       1661.8  -    1669.0  MHz  
Hydroxyl radical (OH)                   1720.530 MHz       1714.8  -    1722.2  MHz  
Methyladyne (CH)                        3263.794 MHz       3242.4  -    3267.1  MHz  
Methyladyne (CH)                        3335.481 MHz       3324.4  -    3338.8  MHz  
Methyladyne (CH)                        3349.193 MHz       3338.0  -    3352.5  MHz  
Formaldehyde (H2CO)                	    4829.660 MHz       4813.6  -    4834.5  MHz 
Methanol (CH3OH)                        6668.518 MHz       6661.8  -    6675.2  MHz 
Helium (3He+)                           8665.650 MHz       8657.0  -    8674.3  MHz
Methanol (CH3OH)                          12.178 GHz         12.17 -      12.19 GHz  
Formaldehyde (H2CO)                       14.488 GHz         14.44 -      14.50 GHz  
Cyclopropenylidene (C3H2)                 18.343 GHz         18.28 -      18.36 GHz  
Cyclopropenylidene (C3H2)                 21.587 GHz         21.56 -      21.61 GHz  
Water vapor (H2O)                         22.235 GHz         22.16 -      22.26 GHz  
Dicarbon monosulphide (CCS)               22.344 GHz         22.32 -      22.37 GHz  
Ammonia (NH3)                             23.694 GHz         23.61 -      23.72 GHz  
Ammonia (NH3)                             23.723 GHz         23.64 -      23.75 GHz  
Ammonia (NH3)                             23.870 GHz         23.79 -      23.89 GHz  
Ammonia (NH3)                             24.139 GHz         24.11 -      24.16 GHz  
Methanol (CH3OH)                          36.169 GHz         36.13 -      36.21 GHz  
Cyanoacetylene (HC3N)                     36.392 GHz         36.36 -      36.43 GHz 
Silicon monoxide (SiO)                    42.519 GHz         42.47 -      42.57 GHz
Silicon monoxide (SiO)                    42.821 GHz         42.77 -      42.86 GHz  
Silicon monoxide (SiO)                    42.880 GHz         42.83 -      42.93 GHz
Silicon monoxide (SiO)                    43.122 GHz         43.07 -      43.17 GHz  
Silicon monoxide (SiO)                    43.424 GHz         43.37 -      43.47 GHz  
Dicarbon monosulphide (CCS)               45.379 GHz         45.33 -      45.42 GHz  
Cyanoacetylene (HC3N)                     45.490 GHz         45.44 -      45.54 GHz 
Carbon monosulphide (13CS)                46.247 GHz         46.20 -      46.29 GHz  
Carbon monosulphide (C34S)                48.207 GHz         48.16 -      48.26 GHz  
Carbon monosulphide (CS)                  48.991 GHz         48.83 -      49.04 GHz  
Oxygen (O2)                               56.265 GHz         56.21 -      56.32 GHz  
Oxygen (O2)                               58.324 GHz         58.27 -      58.38 GHz  
Oxygen (O2)                               58.446 GHz         58.39 -      58.50 GHz  
Oxygen (O2)                               59.164 GHz         59.10 -      59.22 GHz  
Oxygen (O2)                               59.591 GHz         59.53 -      59.65 GHz  
Oxygen (O2)                               60.306 GHz         60.25 -      60.37 GHz  
Oxygen (O2)                               60.434 GHz         60.37 -      60.49 GHz  
Oxygen (O2)                               61.151 GHz         61.09 -      61.21 GHz  
Oxygen (O2)                               62.486 GHz         62.42 -      62.55 GHz  
Deuterated formylium (DCO+)               72.039 GHz         71.97 -      72.11 GHz  
Deuterium cyanide (DCN)                   72.415 GHz         72.34 -      72.49 GHz  
Cyanoacetylene (HC3N)                     72.784 GHz         72.71 -      72.86 GHz 
Methyl cyanide (CH3CN)                    73.59  GHz         73.51 -      73.66 GHz  
Deuterated water (HDO)                    80.578 GHz         80.50 -      80.66 GHz  
Cyanoacetylene (HC3N)           	      81.881 GHz         81.80 -      81.96 GHz  
Cyclopropenylidene (C3H2)                 82.966 GHz         82.88 -      83.05 GHz  
Cyclopropenylidene (C3H2)                 85.339 GHz         85.05 -      85.42 GHz  
Methyl acetylene (CH3CCH)                 85.5   GHz         85.41 -      85.59 GHz  
Deuterated Ammonia (NH2D)                 85.926 GHz         85.84 -      86.01 GHz  
Hydrogen cyanide (HC15N)                  86.055 GHz         85.97 -      86.14 GHz  
Silicon monoxide (SiO)                    86.243 GHz         86.16 -      86.33 GHz  
Hydrogen cyanide (H13CN)                  86.340 GHz         86.25 -      86.43 GHz  
Formylium (H13CO+)                         86.754 GHz         86.67 -      86.84 GHz  
Hydrogen isocyanide (HN13C)               87.091 GHz         87.00 -      87.18 GHz  
Silicon monoxide (SiO)                    86.847 GHz         86.76 -      86.93 GHz  
Ethynyl radical (C2H)                     87.300 GHz         87.21 -      87.39 GHz  
Hydrogen cyanide (HCN)                    88.632 GHz         88.34 -      88.72 GHz  
Hydrogen isocyanide (H15NC)               88.866 GHz         88.78 -      88.95 GHz  
Formylium (HCO+)                          89.189 GHz         88.89 -      89.28 GHz 
Hydrogen isocyanide (HNC)                 90.664 GHz         90.57 -      90.75 GHz  
Cyanoacetylene (HC3N)                     90.979 GHz         90.89 -      91.07 GHz
Methyl cyanide (CH3CN)                    91.98  GHz         91.88 -      92.07 GHz  
Carbon monosulphide (13CS)                92.494 GHz         92.40 -      92.59 GHz 
Diazenylium (N2H+)                        93.174 GHz         93.08 -      93.27 GHz  
Carbon monosulphide (C34S)                96.413 GHz         96.32 -      96.51 GHz  
Carbon monosulphide (CS)                  97.981 GHz         97.65 -      98.08 GHz  
Sulphur monoxide (SO)                     99.300 GHz         99.20 -      99.40 GHz  
Cyanoacetylene (HC3N)                    100.076 GHz         99.98 -     100.18 GHz  
Methyl acetylene (CH3CCH)                102.5   GHz        102.39 -     102.60 GHz  
Cyanoacetylene (HC3N)       	         109.174 GHz        109.06 -     109.28 GHz  
Sulphur monoxide (SO)                    109.252 GHz        109.14 -     109.36 GHz  
Carbon monoxide (C18O)                   109.782 GHz        109.67 -     109.89 GHz  
Deuterated Ammonia (NH2D)                110.153 GHz        110.04 -     110.26 GHz  
Carbon monoxide (13CO)                   110.201 GHz        119.83 -     110.31 GHz  
Methyl cyanide (CH3CN)                   110.38  GHz        110.27 -     110.49 GHz  
Carbon monoxide (C17O)                   112.359 GHz        112.25 -     112.47 GHz  
Cyano radical (CN)                       113.500 GHz        113.39 -     113.61 GHz  
Carbon monoxide (CO)                     115.271 GHz        114.88 -     115.39 GHz  
Oxygen (O2)                              118.750 GHz        118.63 -     118.87 GHz  
Silicon monoxide (SiO)                   127.269 GHz        127.14 -     127.40 GHz  
Formaldehyde (H213CO)                    137.450 GHz        137.31 -     137.59 GHz  
Carbon monosulphide (13CS)               138.739 GHz        138.60 -     138.88 GHz  
Formaldehyde (H2CO)                      140.840 GHz        140.69 -     140.98 GHz  
Deuterated formylium (DCO+)              144.077 GHz        143.93 -     144.22 GHz  
Deuterium cyanide (DCN)                  144.828 GHz        144.68 -     144.97 GHz  
Formaldehyde (H2CO)                      145.603 GHz        145.45 -     145.75 GHz  
Carbon monosulphide (CS)                 146.969 GHz        146.48 -     147.12 GHz  
Methyl cyanide (CH3CN)                   147.17  GHz        147.02 -     147.32 GHz  
Nitric oxide (NO)                        150.4   GHz        149.95 -     150.85 GHz  
Formaldehyde (H2CO)                      150.498 GHz        150.35 -     150.65 GHz  
Methyl acetylene (CH3CCH)                153.8   GHz        153.64 -     153.95 GHz 
Cyanoacetylene (HC3N)                    154.657 GHz        154.50 -     154.81 GHz 
Cyanoacetylene (HC3N)                    163.753 GHz        163.59 -     163.92 GHz 
Hydrogen sulphide (H2S)                  168.760 GHz        168.59 -     168.93 GHz 
Silicon monoxide (SiO)                   173.688 GHz        173.51 -     173.86 GHz  
Water vapor (H2O)                        183.310 GHz        183.13 -     183.49 GHz  
Carbon monosulphide (CS)                 195.954 GHz        195.30 -     196.15 GHz  

Water vapor (H218O)                       203.132 GHz        202.93 -     203.34 GHz  
Sulphur monoxide (SO)                    206.176 GHz        205.97 -     206.38 GHz  
Sulphur monoxide (SO)                    215.221 GHz        215.01 -     215.44 GHz  
Deuterated formylium (DCO+)              216.113 GHz        215.90 -     216.33 GHz  
Silicon monoxide (SiO)                   217.105 GHz        216.89 -     217.32 GHz  
Deuterium cyanide (DCN)                  217.239 GHz        217.02 -     217.46 GHz  
Formaldehyde (H2CO)                      218.222 GHz        218.00 -     218.44 GHz  
Carbon monoxide (C18O)                   219.560 GHz        219.34 -     219.78 GHz  
Carbon monoxide (13CO)                   220.399 GHz        219.67 -     220.62 GHz  
Methyl cyanide (CH3CN)                   220.7   GHz        220.48 -     220.92 GHz  
Sulphur dioxide (SO2)                    221.965 GHz        221.74 -     222.19 GHz  
Methyl acetylene (CH3CCH)                222.1   GHz        221.87 -     222.32 GHz  
Carbon monoxide (C17O)                   224.714 GHz        224.49 -     224.94 GHz  
Sulphur dioxide (SO2)                    225.154 GHz        224.93 -     225.38 GHz  
Deuterated water (HDO)                   225.897 GHz        225.67 -     226.12 GHz   
Cyano radical (CN)                       226.600 GHz        226.37 -     226.83 GHz  
Cyano radical (CN)                       226.800 GHz        226.57 -     227.03 GHz  
Carbon monoxide (CO)                     230.538 GHz        229.77 -     230.77 GHz  
Carbon monosulphide (13CS)               231.221 GHz        230.99 -     231.45 GHz  
Carbon monosulphide (C34S)               241.016 GHz        240.77 -     241.26 GHz  
Deuterated water (HDO)                   241.562 GHz        241.32 -     241.80 GHz  
Methanol (CH3OH)                         241.700 GHz        241.46 -     241.94 GHz  
Methanol (CH3OH)                         241.767 GHz        241.53 -     242.01 GHz  
Methanol (CH3OH)                         241.791 GHz        241.55 -     242.03 GHz  
Methanol (CH3OH)                         241.842 GHz        241.60 -     242.08 GHz  
Carbon monosulphide (CS)                 244.953 GHz        244.14 -     245.20 GHz  
Nitric oxide (NO)                        250.6   GHz        250.35 -     250.85 GHz  
Sulphur dioxide (SO2)                    251.211 GHz        250.96 -     251.46 GHz  
Methyl cyanide (CH3CN)                   257.5   GHz        257.24 -     257.76 GHz  
Hydrogen cyanide (H13CN)                 259.012 GHz        258.75 -     259.27 GHz  
Formylium (H13CO+)           	         260.255 GHz        259.99 -     260.52 GHz  
Silicon monoxide (SiO)                   260.518 GHz        260.26 -     260.78 GHz  
Hydrogen isocyanide (HN13C)              261.263 GHz        261.00 -     261.52 GHz  
Ethynyl radical (C2H)                    262.000 GHz        261.74 -     262.26 GHz  
Sulphur dioxide (SO2)                    262.334 GHz        262.07 -     262.60 GHz  
Hydrogen cyanide (HCN)                   265.886 GHz        265.00 -     266.15 GHz  
Formylium (HCO+)                         267.557 GHz        266.66 -     267.82 GHz  
Hydrogen isocyanide (HNC)                271.981 GHz        271.71 -     272.25 GHz  
Carbon monosulphide (13CS)               277.455 GHz        277.18 -     277.73 GHz  
Diazenylium (N2H+)                       279.511 GHz        279.23 -     279.79 GHz  
Carbon monosulphide (C34S)               289.209 GHz        288.92 -     289.50 GHz  
Sodium hydride (NaH)                     289.860 GHz        289.57 -     290.15 GHz  
Carbon monosulphide (CS)                 293.912 GHz        292.93 -     294.21 GHz  

Hydronium (H3O+)                         307.192 GHz        306.88 -     307.50 GHz  
Carbon monosulphide (13CS)               323.685 GHz        323.36 -     324.01 GHz  
Water vapor (H2O)                        325.153 GHz        324.83 -     325.48 GHz  
Heavy water (HDO)                        313.750 GHz        313.44 -     314.06 GHz  
Carbon monoxide (C18O)                   329.330 GHz        329.00 -     329.66 GHz  
Carbon monoxide (13CO)                   330.587 GHz        329.49 -     330.92 GHz  
Carbon monosulphide (C34S)               337.397 GHz        337.06 -     337.73 GHz  
Cyano radical (CN)                       340.030 GHz        339.69 -     340.37 GHz  
Cyano radical (CN)                       340.250 GHz        339.91 -     340.59 GHz  
Carbon monosulphide (CS)                 342.883 GHz        341.74 -     343.23 GHz  
Hydrogen cyanide (HC15N)                 344.200 GHz        343.86 -     344.54 GHz  
Magnesium hydride (MgH)                  344.305 GHz        343.96 -     344.65 GHz  
Hydrogen cyanide (H13CN)                 344.340 GHz        344.00 -     344.68 GHz  
Carbon monoxide (CO)                     345.796 GHz        344.64 -     346.14 GHz  
Formylium (H13CO+)                        346.999 GHz        346.65 -     347.35 GHz  
Silicon monoxide (SiO)                   347.331 GHz        346.98 -     347.68 GHz  
Ethynyl radical (C2H)                    349.340 GHz        348.99 -     349.69 GHz  
Ethynyl radical (C2H)                    349.390 GHz        349.04 -     349.74 GHz  
Hydrogen cyanide (HCN)                   354.484 GHz        353.30 -     354.84 GHz  
Formylium (HCO+)                         356.734 GHz        355.54 -     357.09 GHz  
Hydrogen isocyanide (HNC)                362.630 GHz        362.27 -     362.99 GHz  
Hydronium (H3O+)                         364.797 GHz        364.43 -     365.16 GHz  
Oxygen (O2)                              368.498 GHz        368.13 -     368.87 GHz  
Carbon monosulphide (13CS)               369.908 GHz        369.54 -     370.28 GHz  
H2D+                                     372.421 GHz        372.05 -     372.79 GHz  
Diazenylium (N2H+)                       372.672 GHz        372.30 -     373.04 GHz  
Water vapor (H2O)                        380.197 GHz        379.82 -     380.58 GHz  
Carbon monosulphide (C34S)               385.578 GHz        385.19 -     385.96 GHz  
Hydronium (H3O+)                         388.459 GHz        388.07 -     388.85 GHz  
Water vapor (H218O)                      390.608 GHz        390.22 -     391.00 GHz  
Silicon monoxide (SiO)                   390.728 GHz        390.34 -     391.12 GHz  
Carbon monosulphide (CS)                 391.847 GHz        390.54 -     392.24 GHz  
Hydronium (H3O+)                         396.272 GHz        395.88 -     396.67 GHz  

Carbon monosulphide (13CS)               416.123 GHz        415.71 -     416.54 GHz  
Oxygen (O2)                              424.763 GHz        424.34 -     425.19 GHz  
Hydrogen cyanide (H13CN)                 431.660 GHz        431.23 -     432.09 GHz  
Carbon monosulphide (C34S)               433.751 GHz        433.32 -     434.19 GHz  
Silicon monoxide (SiO)                   434.120 GHz        433.69 -     434.55 GHz  
Carbon monoxide (C18O)                   439.088 GHz        438.65 -     439.53 GHz  
Water vapor (H2O)                        439.151 GHz        438.71 -     439.59 GHz  
Carbon monoxide (13CO)                   440.765 GHz        439.30 -     441.21 GHz  
Carbon monosulphide (CS)                 440.803 GHz        439.33 -     441.24 GHz  
Hydrogen cyanide (HCN)                   443.123 GHz        441.65 -     443.57 GHz  
Lithium hydride (LiH)                    443.957 GHz        443.51 -     444.40 GHz  
Water vapor (H2O)                        448.001 GHz        447.55 -     448.45 GHz  
Hyrogen Sulphide (H2S)                   452.390 GHz        451.94 -     452.84 GHz  
Hydrogen isocyanide (HNC)                453.270 GHz        452.82 -     453.72 GHz  
Carbon monoxide (CO)                     461.041 GHz        459.50 -     461.50 GHz  
Carbon monosulphide (13CS)               462.331 GHz        461.87 -     462.79 GHz  
NH2                                      462.400 GHz        461.94 -     462.86 GHz  
Heavy water (HDO)                        464.925 GHz        464.46 -     465.39 GHz  
NH2                                      469.300 GHz        468.83 -     469.77 GHz  
Water vapor (H2O)                        474.689 GHz        474.21 -     475.16 GHz  
Silicon monoxide (SiO)                   477.503 GHz        477.03 -     477.98 GHz  
Heavy water (HDO)                        479.947 GHz        479.47 -     480.43 GHz  
Heavy water (HDO)                        481.780 GHz        481.30 -     482.26 GHz  
Carbon monosulphide (C34S)               481.916 GHz        481.43 -     482.40 GHz  
Oxygen (O2)                              487.249 GHz        486.76 -     487.74 GHz  
Water vapor (H218O)                       489.054 GHz        488.56 -     489.54 GHz  
Carbon monosulphide (CS)                 489.751 GHz        488.12 -     490.24 GHz  
Heavy water (HDO)                        490.597 GHz        490.11 -     491.09 GHz  
Carbon (CI)                              492.162 GHz        490.52 -     492.65 GHz  

Carbon monosulphide (13CS)                508.528 GHz        508.02 -     509.04 GHz  
Heavy water (HDO)                        509.292 GHz        508.78 -     509.80 GHz  
Hydrogen cyanide (H13CN)                  517.970 GHz        517.45 -     518.49 GHz  
Silicon monoxide (SiO)                   520.878 GHz        520.36 -     521.40 GHz  
Carbon monosulphide (C34S)                530.071 GHz        529.54 -     530.60 GHz  
Hydrogen cyanide (HCN)                   531.716 GHz        529.94 -     532.25 GHz  
Methylidyne (CH)                         532.700 GHz        532.17 -     533.23 GHz  
SiH2                                      536.600 GHz        536.06 -     537.14 GHz  
Methylidyne (CH)                         536.800 GHz        536.26 -     537.34 GHz  
Carbon monosulphide (CS)                 538.689 GHz        536.89 -     539.23 GHz  
Hydrogen isocyanide (HNC)                543.897 GHz        543.35 -     544.44 GHz  
Water vapor (H218O)                       547.676 GHz        547.13 -     548.22 GHz  
Carbon monoxide (13CO)                    550.926 GHz        549.09 -     551.48 GHz  
Carbon monosulphide (13CS)                554.715 GHz        554.16 -     555.27 GHz  
Water vapor (H2O)                         556.936 GHz        556.38 -     557.49 GHz  
Silicon monoxide (SiO)                   564.244 GHz        563.68 -     564.81 GHz  
Ammonia (15NH3)                           572.113 GHz        571.54 -     572.69 GHz  
Ammonia (NH3)                             572.498 GHz        571.93 -     573.07 GHz  
SiH2                                      575.800 GHz        575.22 -     576.38 GHz  
Carbon monoxide (CO)                     576.268 GHz        574.35 -     576.84 GHz  
Carbon monosulphide (C34S)                578.216 GHz        577.64 -     578.79 GHz  
Sodium Hydride (NaH)                     579.480 GHz        578.90 -     580.06 GHz  
Carbon monosulphide (CS)                 587.616 GHz        587.03 -     588.20 GHz  
Heavy water (HDO)                        599.927 GHz        599.33 -     600.53 GHz  

Carbon monosulphide (13CS)                600.889 GHz        600.29 -     601.49 GHz  
Hydrogen cyanide (H13CN)                  604.268 GHz        603.66 -     604.87 GHz  
Silicon monoxide (SiO)                   607.599 GHz        606.99 -     608.21 GHz  
Hydrogen cyanide (HCN)                   620.304 GHz        618.24 -     620.92 GHz  
Water vapor (H2O)                         620.700 GHz        620.08 -     621.32 GHz  
Heavy water (HDO)                        622.483 GHz        621.86 -     623.11 GHz  
Silicon hydride (SiH)                    624.900 GHz        624.27 -     625.53 GHz  
Hydrogen chloride (HCl)                  625.040 GHz        624.41 -     625.67 GHz  
Hydrogen chloride (HCl)                  625.980 GHz        625.35 -     626.61 GHz  
Carbon monosulphide (C34S)                626.349 GHz        625.72 -     626.98 GHz  
Silicon hydride (SiH)                    627.700 GHz        627.07 -     628.33 GHz  
Hydrogen isocyanide (HNC)                634.510 GHz        633.88 -     635.14 GHz  
Carbon monosulphide (CS)                 636.532 GHz        634.41 -     637.17 GHz  
Carbon monosulphide (13CS)                647.050 GHz        646.40 -     647.70 GHz  
H2D+                                      648.337 GHz        647.69 -     648.99 GHz  
Silicon monoxide (SiO)                   650.944 GHz        650.29 -     651.60 GHz  
Carbon monoxide (13CO)                    661.067 GHz        658.86 -     661.73 GHz  
Carbon monosulphide (C34S)                674.470 GHz        673.80 -     675.14 GHz  
Carbon monosulphide (CS)                 685.435 GHz        683.15 -     686.12 GHz  
Magnesium hydride (MgH)                  687.100 GHz        686.41 -     687.79 GHz  
Magnesium hydride (MgH)                  687.900 GHz        687.21 -     688.59 GHz  
Hydrogen cyanide (H13CN)                  690.268 GHz        689.58 -     690.96 GHz  
Carbon monoxide (CO)                     691.473 GHz        689.17 -     692.16 GHz  
Carbon monosulphide (13CS)                693.195 GHz        692.50 -     693.89GHz  
Silicon monoxide (SiO)                   694.275 GHz        693.58 -     694.97 GHz  

Hydrogen cyanide (HCN)                   708.877 GHz        708.17 -     709.59 GHz  
Oxygen (O2)                               715.393 GHz        714.68 -     716.11 GHz  
Carbon monosulphide (C34S)                722.577 GHz        721.85 -     723.30 GHz  
Hydrogen isocyanide (HNC)                725.107 GHz        724.38 -     725.83 GHz  
Carbon monosulphide (CS)                 734.324 GHz        733.59 -     735.06 GHz  
Silicon monoxide (SiO)                   737.594 GHz        736.86 -     738.33 GHz  
Carbon monosulphide (13CS)                739.324 GHz        738.58 -     740.06 GHz  
Water vapor (H218O)                       745.320 GHz        744.57 -     746.07 GHz  
Water vapor (H2O)                         752.033 GHz        751.28 -     752.79 GHz  
Heavy water (HDO)                        753.411 GHz        752.66 -     754.16 GHz  
Carbon monosulphide (C34S)                770.669 GHz        769.90 -     771.44 GHz  
Oxygen (O2)                               773.840 GHz        773.07 -     774.61 GHz  
Hydrogen cyanide (H13CN)                  776.819 GHz        776.04 -     777.60 GHz  
Silicon monoxide (SiO)                   780.594 GHz        779.81 -     781.38 GHz  
Carbon monosulphide (CS)                 783.199 GHz        782.42 -     783.98 GHz  
Carbon monosulphide (13CS)                785.434 GHz        784.65 -     786.22 GHz  
Hydrogen cyanide (HCN)                   797.433 GHz        794.77 -     798.23 GHz

Formylium (HCO+)                         802.653 GHz        799.98 -     803.46 GHz  
Carbon monoxide (CO)                     806.652 GHz        803.96 -     807.46 GHz  
Carbon (CI)                              809.350 GHz        806.65 -     810.16 GHz  
Hydrogen isocyanide (HNC)                815.684 GHz        812.96 -     816.50 GHz  
Carbon monosulphide (C34S)               818.745 GHz        817.93 -     819.56 GHz  
Silicon monoxide (SiO)                   824.186 GHz        823.36 -     825.01 GHz  
Carbon monosulphide (13CS)               831.523 GHz        830.69 -     832.36 GHz  
Carbon monosulphide (CS)                 832.057 GHz        829.28 -     832.89 GHz  
Oxygen (O2)                              834.146 GHz        833.31 -     834.98 GHz  
Methylidinium (CH+)                      835.070 GHz        834.23 -     835.91 GHz  
Hydrogen cyanide (H13CN)                 863.069 GHz        862.21 -     863.93 GHz  
Carbon monosulphide (C34S)               866.804 GHz        865.94 -     867.67 GHz  
Sulpher hydride (SH)                     866.900 GHz        866.03 -     867.77 GHz  
Silicon monoxide (SiO)                   867.457 GHz        866.59 -     868.33 GHz  
Sulpher hydride (SH)                     875.200 GHz        874.32 -     876.08 GHz  
Carbon monosulphide (13CS)               877.591 GHz        876.71 -     878.47 GHz  
Carbon monosulphide (CS)                 880.899 GHz        877.96 -     881.78 GHz  
Carbon monoxide (13CO)                   881.273 GHz        878.33 -     882.15 GHz  
Hydrogen cyanide (HCN)                   885.977 GHz        883.02 -     886.86 GHz  
Lithium hydride (LiH)                    886.500 GHz        885.61 -     887.39 GHz  
Formilium (HCO+)                         891.558 GHz        888.59 -     892.45 GHz  
Heavy water (HDO)                        893.639 GHz        892.74 -     894.53 GHz  

Hydrogen isocyanide (HNC)                906.239 GHz        905.33 -     907.15 GHz  
Silicon monoxide (SiO)                   910.710 GHz        909.80 -     911.62 GHz  
Carbon monosulphide (C34S)               914.844 GHz        913.93 -     915.76 GHz  
Water vapor (H2O)                        916.172 GHz        915.26 -     917.09 GHz  
Heavy water (HDO)                        919.310 GHz        918.39 -     920.23 GHz  
Carbon monoxide (CO)                     921.800 GHz        918.72 -     922.72 GHz  
Carbon monosulphide (13CS)               923.633 GHz        922.71 -     924.56 GHz  
Carbon monosulphide (CS)                 929.723 GHz        926.62 -     930.65 GHz  
Hydrogen cyanide (H13CN)                 949.299 GHz        948.35 -     950.25 GHz  
Silicon monoxide (SiO)                   953.943 GHz        952.99 -     954.90 GHz  
H3+                                      955.000 GHz        954.04 -     955.96 GHz  
Carbon monosulphide (C34S)               962.865 GHz        961.90 -     963.83 GHz  
Carbon monosulphide (13CS)               969.649 GHz        968.68 -     970.62 GHz  
Water vapor (H2O)                        970.315 GHz        969.34 -     971.29 GHz  
Nitrogen hydride (NH)                    974.479 GHz        973.50 -     975.45 GHz  
Hydrogen cyanide (HCN)                   974.488 GHz        971.24 -     975.46 GHz  
Carbon monosulphide (CS)                 978.529 GHz        977.55 -     979.51 GHz  
Formilium (HCO+)                         983.925 GHz        980.64 -     984.91 GHz  
Heavy water (HDO)                        984.138 GHz        983.15 -     985.12 GHz  
Hydronium (H3O+)                         984.697 GHz        983.71 -     985.68 GHz  
Water vapor (H2O)                        987.927 GHz        986.94 -     988.92 GHz  
Water vapor (H218O)                      994.634 GHz        993.64 -     995.63 GHz  
Heavy water (HDO)                        995.412 GHz        994.42 -     996.41 GHz  
Hydrogen isocyanide (HNC)                996.771 GHz        995.77 -     997.77 GHz  
Silicon monoxide (SiO)                   997.155 GHz        996.16 -     998.15 GHz  


Last modified: November 17, 2003