J/A+A/576/A39 THz spectrum of the monodeuterated methyl formate (Duan+, 2015)
THz extended spectrum of the monodeuterated methyl formate (DCOOCH3).
Duan C., Carvajal M., Yu S., Pearson J.C., Drouin B.J., Kleiner I.
<Astron. Astrophys. 576, A39 (2015)>
=2015A&A...576A..39D 2015A&A...576A..39D
ADC_Keywords: Interstellar medium ; Spectra, millimetric/submm
Keywords: molecular data - methods: laboratory: molecular -
methods: data analysis - ISM: molecules - submillimeter: ISM
Abstract:
Laboratory spectral recordings and accurate molecular spectral
analysis of any potential interstellar molecule are essential to
generate a complete spectroscopic line list. This permits the
prediction of the frequencies and intensities of any transition for
its subsequent identification in the interstellar medium. Present
analysis of DCOOCH3 is aimed to provide a comprehensive spectral
catalog that encompasses as much as possible the frequency coverage of
the new generation far-IR and submillimeter wave observation
facilities. A new measurement of the rotational spectrum of DCOOCH3
has been carried out in the JPL laboratory in the frequency range from
0.85 to 1.5 THz. The new data were analyzed jointly with literature
data using the Rho Axis Method (RAM), a tool developed for the
spectral analysis of molecules with large amplitude internal CH3
rotors. Twenty seven spectroscopic constants of DCOOCH3 have been
fitted to 3763 transitions with maximum values of J=69 and Ka=36 of
the ground torsional state with a standard (unitless) deviation of
0.97. With respect to prior work, this is a significantly better
result that was obtained with 2060 more transitions while also
achieving a better accuracy for the new parameter values.
Description:
A new measurement of the rotational spectrum of DCOOCH3 has been
carried out in the JPL laboratory in the frequency range from 0.85 to
1.5THz. The new data were analyzed jointly with literature data using
the Rho Axis Method (RAM). 3763 lines are assigned for the ground
torsional states from the monodeuterated methyl formate species
(DCOOCH3) with a good accuracy.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 117 3763 *Data for methyl formate isotopologue DCOOCH3
transitions from vt=0 torsional states included
in the fit with parameters of Table 2
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Note on table1.dat: Assignments, observed frequencies, calculated frequencies
from the RAM fit, residuals, line strengths, and lower state energy levels
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See also:
J/A+A/500/1109 : Rotational spectrum of HCOO13CH3 (Carvajal+, 2009)
J/A+A/538/A119 : Spectrum of 18O-methyl formate HCO18OCH3 (Tercero+ 2012)
J/A+A/568/A58 : HCOO13CH3 rotational spectrum (Haykal+, 2014)
J/ApJ/714/1120 : Rotational spectrum and DCOOCH3 in Orion (Margules+, 2010)
J/ApJ/770/L13 : Detection in Orion of CH3COOCH3 (Tercero+, 2013)
J/ApJS/190/315 : Rotational spectrum of H13COOCH3 (Carvajal+, 2010)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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4 I1 --- vt1 [0] Upper torsional quantum number (1)
7- 8 I2 --- J1 [1/69] Upper total angular momentum (1)
10- 12 I3 --- Ka1 [-36/36] Upper Ka rotational quantum number (1)
15- 16 I2 --- Kc1 [0/64] Upper Kc rotational quantum number (1)
18 A1 --- p1 [±] Upper parity (1)
22 I1 --- vt0 [0] Lower torsional quantum number (1)
24- 26 I3 --- J0 [0/69] Lower total angular momentum (1)
28- 30 I3 --- Ka0 [-36/36] Lower Ka rotational quantum number (1)
33- 34 I2 --- Kc0 [0/64] Lower Kc rotational quantum number (1)
36 A1 --- p0 [±] Lower parity (1)
39- 49 F11.3 MHz oFreq [4264/1477945] Observed frequency
51- 53 I3 kHz e_oFreq [3/200] Uncertainty in oFreq
57- 67 F11.3 MHz cFreq [4264/1477945] Calculated frequency
69- 74 I6 kHz e_cFreq [0/205] Uncertainty in cFreq
80- 85 F6.3 MHz O-C [-0.5/0.5] Differences among oFreq and cFreq
92- 99 F8.3 D+2 Lstr [0/200] Line strength; see text for details
101-109 F9.4 cm-1 E0 [0/1309] Lower state energy (2)
111-117 A7 --- Ref References of data; see text for details
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Note (1): Upper and lower state quantum numbers are indicated here by 1 and 0
respectively. Torsion-rotation levels of A species have a "parity" label;
levels of E species have a signed Ka value (Herbst et al., 1984,
J. Mol. Spectrosc., 108, 42).
Note (2): Lower state energy (cm-1) referred to the J=Ka=0 A-species energy
level taken as the zero of the energy
(zero-point torsional energy: 66.0967cm-1).
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Acknowledgements:
Miguel Carvajal, miguel.carvajal(at)dfa.uhu.es, U. Huelva, Spain
Isabelle Keilner, LISA, France
(End) I. Kleiner [LISA], M. Carvajal [U. Huelva], P. Vannier [CDS] 28-Jan-2015