Access to Astronomical Catalogues

J/A+A/544/A19       CH2NH accurate rotational rest frequencies (Dore+, 2012)
Accurate rotational rest frequencies of CH2NH at submillimetre wavelengths.
    Dore L., Bizzocchi L., Degli Esposti C.
   <Astron. Astrophys. 544, A19 (2012)>
   =2012A&A...544A..19D
ADC_Keywords: Atomic physics ; Spectroscopy

Keywords: molecular data - methods: laboratory - techniques: spectroscopic -
          radio lines: ISM

Abstract:
    Methanimine (CH2NH) has been detected in different astronomical
    sources, both galactic (as in several "hot cores", the circumstellar
    enevolope IRC+10216, and the L183 pre-stellar core) and extragalactic,
    and is considered a pre-biotic interstellar molecule. Its ground-state
    rotational spectrum has been studied in the laboratory up to 172GHz,
    well below the spectral ranges covered by Herschel/HIFI and the ALMA
    bands 9 and 10.

    In this laboratory study, we extend into the submillimetre-wave region
    the detection of the rotational spectrum of CH2NH in its vibrational
    ground state.

Description:
    Table 1 lists the transition frequencies of methanimine measured in
    laboratory along with their estimated uncertainties and the residuals
    from a weighted fit using Watson's S-reduced Ir representation. The
    last 84 records report the newly observed transitions recorded by
    means of a submillimetre-wave spectrometer, the other observations are
    from Dore et al. (2010JMoSp.263...44D).

    Table 3 is an expansion of the article's Table3 reporting rest
    frequencies and line strengths of the strongest transitions at 50K in
    the region 0.4-1THz

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat        60      210   Observed hyperfine frequencies and residuals
                              of CH2NH
table3.dat        48      314   Calculated hyperfine frequencies of CH2NH


See also:
 J/A+A/425/767  : HC5N vibrationally excited states (Yamada+, 2004)
 J/A+A/413/1177 : Spectroscopy of N2D+ hyperfine structure (Dore+, 2004)
 J/A+A/455/1161 : Rest frequencies of sub-mm spectrum of SiN (Bizzocchi+, 2006)
 J/A+A/492/875  : Rest frequencies for C3O (Bizzocchi+, 2008)


Byte-by-byte Description of file: table1.dat

   Bytes Format Units   Label   Explanations

   1-  3  I3    ---     J'      [0/36] Upper state rotational quantum number
   4-  6  I3    ---     K'a     [0/9] Upper state K quantum number
   7-  9  I3    ---     K'c     [0/32] Upper state K quantum number
  10- 12  I3    ---     J       [0/36] Lower state rotational quantum number
  13- 15  I3    ---     Ka      [0/9] Lower state K quantum number
  16- 18  I3    ---     Kc      [0/32] Lower state K quantum number
  19- 21  I3    ---     F'N     [0/36]? Upper state FN=J+IN quantum number
  22- 24  I3    ---     FN      [0/36]? Lower state F quantum number
  25- 27  I3    ---     2F'H1   [1/19]? Upper state FH1=FN+IH1
                                      quantum number (x2)
  28- 29  A2    ---     ---     [/2 ]
  30- 32  I3    ---     2FH1    [1/19]? Lower state FH1 quantum number (x2)
  33- 34  A2    ---     ---     [/2 ]
  35- 46  F12.4 MHz     Freq    [5288/628741] Observed transition frequencies (1)
  47- 54  F8.4  MHz     O-C     Residuals (2)
  55- 60  F6.3  MHz     e_Freq  Estimated uncertainty of Observed (3)

Note (1): The frequency of blended transitions or hf components was calculated
     as the sum of individual frequencies weighted by the relative intensities.
Note (2): The rms error of residuals of the global fit is 22kHz.

Note (3): The fit standard deviation is 0.971.



Byte-by-byte Description of file: table3.dat

   Bytes Format Units   Label     Explanations

   1-  3  I3    ---     J'        [0/36] Upper state rotational quantum number
   4-  6  I3    ---     K'a       [0/9] Upper state K quantum number
   7-  9  I3    ---     K'c       [0/32] Upper state K quantum number
  10- 12  I3    ---     J         [0/36] Lower state rotational quantum number
  13- 15  I3    ---     Ka        [0/9] Lower state K quantum number
  16- 18  I3    ---     Kc        [0/32] Lower state K quantum number
  19- 21  I3    ---     F'N       [0/36] Upper state FN=J+IN quantum number
  22- 24  I3    ---     FN        [0/36] Lower state FN quantum number
  25- 36  F12.4 MHz     RFreq     [399178/973793] Calculated rest frequency
  37- 40  F4.1  kHz     e_RFreq   rms uncertainty on RFreq
  41- 48  F8.4  ---     LStr      Line strength


Acknowledgements:
    Luca Dore, luca.dore(at)unibo.it
(End) Luca Dore [Dept. Chem., Bologna, Italy] Patricia Vannier [CDS] 25-Jun-2012