J/A+A/629/A35 Succinonitrile and excited states spectroscopy (Cabezas+, 2019)
The millimeter-wave spectrum and astronomical search of succinonitrile and
its vibrational excited states.
Cabezas C., Bermudez C., Gallego J.D., Tercero B., Hernandez J.M.,
Tanarro I., Herrero V.J., Domenech J.L., Cernicharo J.
<Astron. Astrophys. 629, A35 (2019)>
=2019A&A...629A..35C 2019A&A...629A..35C (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: ISM: molecules - methods: laboratory: molecular - molecular data -
line: identification
Abstract:
Dinitriles with a saturated hydrocarbon skeleton and a -CN group at
each end can have large electric dipole moments. Their formation can
be related to highly reactive radicals such as CH2CN, C2N or CN.
Thus, these saturated dinitriles are potential candidates to be
observed in the ISM. Our goal is the investigation of the rotational
spectrum of one of the simplest dinitriles NC-CH2-CH2-CN,
succinonitrile, whose actual rotational parameters are not precise
enough to allow its detection it in the ISM. In addition, the
rotational spectra for its vibrational excited states will be
analyzed.
The rotational spectra of succinonitrile was measured in the frequency
range 72-116.5GHz using a new broadband millimeter-wave spectrometer
based on radio astronomy receivers with Fast Fourier Transform
backends. The identification of the vibrational excited states of
succinonitrile was supported by high-level ab initio calculations on
the harmonic and anharmonic force fields.
A total of 459 rotational transitions with maximum values of J and Ka
quantum numbers 70 and 14, respectively, were measured for the ground
vibrational state of succinonitrile.
The analysis allowed us to accurately determine the rotational,
quartic and sextic centrifugal distortion constants. Up to eleven
vibrational excited states, resulted from the four lowest frequency
vibrational modes nu13, nu12, nu24 and nu23 were identified. In
addition to the four fundamental modes, we observed overtones together
with some combination states.
The rotational parameters for the ground state were employed to
unsuccessfully search for succinonitrile in the cold and warm
molecular clouds Orion KL, Sgr B2(N), B1-b and TMC-1,using the
spectral surveys captured by IRAM 30m at 3mm and the Yebes 40m at
1.3cm and 7mm.
Description:
tablea1.dat contains measured transition frequencies of the ground
state of succinonitrile from 72-116GHz.
tablea2.dat contains measured transition frequencies of the nu13
vibrational excited state of succinonitrile from 72-116GHz.
tablea3.dat contains measured transition frequencies of the nu12
vibrational excited state of succinonitrile from 72-116GHz.
tablea4.dat contains measured transition frequencies of the 2nu13
vibrational excited state of succinonitrile from 72-116GHz.
tablea5.dat contains measured transition frequencies of the nu13+nu12
vibrational excited state of succinonitrile from 72-116GHz.
tablea6.dat contains measured transition frequencies of the nu24
vibrational excited state of succinonitrile from 72-116GHz.
tablea7.dat contains measured transition frequencies of the 3nu13
vibrational excited state of succinonitrile from 72-116GHz.
tablea8.dat contains measured transition frequencies of the 4nu13
vibrational excited state of succinonitrile from 72-116GHz.
tablea9.dat contains measured transition frequencies of the 2nu12
vibrational excited state of succinonitrile from 72-116GHz.
tablea10.dat contains measured transition frequencies of the
2nu13+nu12 vibrational excited state of succinonitrile from 72-116GHz.
tablea11.dat contains measured transition frequencies of the nu13+nu24
vibrational excited state of succinonitrile from 72-116GHz.
tablea12.dat contains measured transition frequencies of the nu23
vibrational excited state of succinonitrile from 72-116GHz.
tablea13.dat contains the predicted transition frequencies of the
ground state of succinonitrile up to 200GHz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 66 459 Measured transitions for the ground state
tablea2.dat 66 351 Measured transitions for the n13 state
tablea3.dat 66 251 Measured transitions for the n12 state
tablea4.dat 66 293 Measured transitions for the 2n13 state
tablea5.dat 66 140 Measured transitions for the n13+nu12 state
tablea6.dat 66 189 Measured transitions for the n24 state
tablea7.dat 66 53 Measured transitions for the 3n13 state
tablea8.dat 66 15 Measured transitions for the 4n13 state
tablea9.dat 66 22 Measured transitions for the 2n12 state
tablea10.dat 66 45 Measured transitions for the 2n13+nu12 state
tablea11.dat 66 52 Measured transitions for the n13+nu24 state
tablea12.dat 66 20 Measured transitions for the n23 state
tablea13.dat 47 9144 Predicted frequencies for the ground state
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Byte-by-byte Description of file: tablea?.dat tablea1[012].dat
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Bytes Format Units Label Explanations
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3- 4 I2 --- J' Quantum number J for upper level
7- 8 I2 --- Ka' Quantum number Ka for upper level
11- 12 I2 --- Kc' Quantum number Kc for upper level
17- 18 I2 --- J" Quantum number J for lower level
21- 22 I2 --- Ka" Quantum number Ka for lower level
25- 26 I2 --- Kc" Quantum number Kc for lower level
31- 41 F11.4 MHz FreqMeas Measured frequency
48- 53 F6.4 MHz e_FreqMeas Uncertainty associated to frequency
60- 66 F7.4 MHz O-C Difference between observed and calculated
frequency
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Byte-by-byte Description of file: tablea13.dat
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Bytes Format Units Label Explanations
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2- 3 I2 --- J' Quantum number J for upper level
6- 7 I2 --- Ka' Quantum number Ka for upper level
10- 11 I2 --- Kc' Quantum number Kc for upper level
14- 15 I2 --- J" Quantum number J for lower level
18- 19 I2 --- Ka" Quantum number Ka for lower level
22- 23 I2 --- Kc" Quantum number Kc for lower level
27- 37 F11.4 MHz Freq Frequency
41- 47 F7.4 [nm2/MHz] logInt Base 10 logarithm of the integrated intensity
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Acknowledgements:
Carlos Cabezas, carlos.cabezas(at)csic.es
(End) Patricia Vannier [CDS] 10-Jul-2019