J/A+A/647/A55 Rotational spectrum of propiolamide (Alonso+, 2021)
Rotational spectroscopic study and astronomical search for propiolamide in
Sgr B2(N).
Alonso E.R., Kolesnikova L., Belloche A., Mata S., Garrod R.T., Jabri A.,
Leon I., Guillemin J.-C., Mueller H.S.P., Menten K.M., Alonso J.L.
<Astron. Astrophys. 647, A55 (2021)>
=2021A&A...647A..55A 2021A&A...647A..55A (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Spectroscopy ; Atomic physics
Keywords: ISM: molecules - astrochemistry - line: identification -
ISM: individual objects: Sagittarius B2 -
astronomical databases: miscellaneous
Abstract:
For all the amides detected in the interstellar medium (ISM), the
corresponding nitriles or isonitriles have also been detected in the
ISM, some of which have relatively high abundances. Among the abundant
nitriles for which the corresponding amide has not yet been detected
is cyanoacetylene (HCCCN), whose amide counterpart is propiolamide
(HCCC(O)NH2).
With the aim of supporting searches for this amide in the ISM, we
provide a complete rotational study of propiolamide from 6GHz to
440GHz.
Time-domain Fourier transform microwave (FTMW) spectroscopy under
supersonic expansion conditions between 6GHz and 18GHz was used to
accurately measure and analyze ground-state rotational transitions
with resolved hyperfine structure arising from nuclear quadrupole
coupling interactions of the 14N nucleus. We combined this technique
with the frequency-domain roomtemperature millimeter wave and
submillimeter wave spectroscopies from 75GHz to 440GHz in order to
record and assign the rotational spectrain the ground state and in
the low-lying excited vibrational states. We used the ReMoCA spectral
line survey performed with the Atacama Large Millimeter/submillimeter
Array toward the star-forming region Sgr B2(N) to search for
propiolamide.
We identified and measured more than 5500 distinct frequency lines of
propiolamide in the laboratory. These lines were fitted using an
effective semi-rigid rotor Hamiltonian with nuclear quadrupole
coupling interactions taken into consideration. We obtained accurate
sets of spectroscopic parameters for the ground state and the three
low-lying excited vibrational states. We report the nondetection of
propiolamide toward the hot cores Sgr B2(N1S) and Sgr B2(N2). We find
that propiolamide is at least 50 and 13 times less abundant than
acetamide in Sgr B2(N1S) and Sgr B2(N2), respectively, indicating that
the abundance difference between both amides is more pronounced by at
least a factor of 8 and 2, respectively, than for their corresponding
nitriles.
Although propiolamide has yet to be included in astrochemical modeling
networks, the observed upper limit to the ratio of propiolamide to
acetamide seems consistent with the ratios of related species as
determined from past simulations. The comprehensive spectroscopic data
presented in this paper will aid future astronomical searches.
Description:
List of the measured transitions in the ground state and three excited
vibrational states of propiolamide.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 101 8708 Fitted rotational transitions of propiolamide in the
ground state and three excited vibrational states
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See also:
J/ApJS/158/188 : Detection of glycolaldehyde toward Sgr B2 (Widicus+, 2005)
J/A+A/559/A47 : Sgr B2(N) and Sgr B2(M) IRAM 30m line survey (Belloche+, 2013)
J/ApJ/812/L5 : CH3NCO (methyl isocyanate) transition frequencies
(Halfen+, 2015)
J/A+A/610/A10 : Sgr B2 los molecular absorption line spectra (Corby+, 2018)
J/A+A/639/A135 : Glycolamide rotational transitions (Sanz-Novo+, 2020)
J/A+A/641/A160 : Hot aminoacetonitrile in Sgr B2 (Melosso+, 2020)
J/A+A/642/A29 : Spectroscopy of CH2(CN)2 and CNCH2CN (Motiyenko+, 2020)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- VibState Vibrational state
10- 12 I3 --- J' Upper state J quantum number
13- 15 I3 --- Ka' Upper state Ka quantum number
16- 18 I3 --- Kc' Upper state Kc quantum number
19- 21 I3 --- F' ? Upper state F quantum number
24- 26 I3 --- J" Lower state J quantum number
27- 29 I3 --- Ka" Lower state Ka quantum number
30- 32 I3 --- Kc" Lower state Kc quantum number
33- 35 I3 --- F" ? Lower state F quantum number
43- 53 F11.4 MHz FreqObs Observed transition frequency
58- 62 F5.3 MHz e_Freq Experimental uncertainty
65- 71 F7.4 MHz O-C Observed minus calculated frequency
81-101 A21 --- Comment Source of the data (1)
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Note (1): Little & Gerry (1978): 1978, J. Mol. Spectrosc., 71, 321.
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Acknowledgements:
Lucie Kolesnikova, lucie.kolesnikova(at)vscht.cz
(End) L. Kolesnikova [UCT Prague, Czech Republic], P. Vannier [CDS] 08-Feb-2021