J/A+A/619/A67 Rotational spectrum of methoxyacetaldehyde (Kolesnikova+, 2018)
Laboratory rotational spectrum and astronomical search for methoxyacetaldehyde.
Kolesnikova L., Pena I., Alonso E.R., Tercero B., Cernicharo J., Mata S.,
Alonso J.L.
<Astron. Astrophys. 619, A67 (2018)>
=2018A&A...619A..67K 2018A&A...619A..67K (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Spectroscopy ; Atomic physics
Keywords: astrochemistry - ISM: molecules - line: identification -
astronomical databases: miscellaneous -
Abstract:
Methoxyacetaldehyde belongs to a group of structural isomers with the
general formula C3H6O2, of which methyl acetate and ethyl
formate are known interstellar molecules. Rotational data available
for methoxyacetaldehyde are limited to 40GHz, which makes predictions
at higher frequencies rather uncertain.
The aim of this work is to provide accurate experimental frequencies
of methoxyacetaldehyde in the millimeter-wave region to support its
detection in the interstellar medium.
The rotational spectrum of methoxyacetaldehyde was recorded at
room-temperature from 75 to 120GHz and from 170 to 310GHz using the
millimeter-wave spectrometer in Valladolid. Additional measurements
were also performed at conditions of supersonic expansion from 6 to
18GHz. The assigned rotational transitions were analyzed using the
S-reduced semirigid-rotor Hamiltonian.
We newly assigned over 1000 lines for the most stable conformer of
methoxyacetaldehyde in its ground state and five lowest excited
vibrational states, and precise sets of spectroscopic constants were
obtained. We searched for spectral features of methoxyacetaldehyde in
the high-mass star-forming regions Orion KL and Sagittarius B2, as
well as in the cold dark cloud Barnard 1 (B1-b). No lines belonging to
methoxyacetaldehyde were detected above the detection limit of our
data. We provide upper limits to the methoxyacetaldehyde colum density
in these sources.
Description:
Observed rotational transitions of methoxyacetaldehyde in the ground
state and excited vibrational states.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table4.dat 126 1353 Fitted rotational transitions of methoxyacetaldehyde
in the ground state and excited vibrational states
--------------------------------------------------------------------------------
See also:
J/A+A/577/A91 : Millimeter wave spectrum of vinyl acetate (Kolesnikova+, 2015)
J/A+A/591/A75 : Millimeter wave spectrum of methyl cyanate (Kolesnikova+ 2016)
J/ApJ/832/42 : Rotational spectrum of vinyl formate (Alonso+, 2016)
J/ApJS/229/26 : Rotational spectra of aminoacetonitrile (Kolesnikova+, 2017)
J/ApJS/233/24 : Iso-propyl cyanide rotational study (Kolesnikova+, 2017)
J/A+A/609/A24 : Rotational spectrum of methoxyamine (Kolesnikova+, 2018)
J/A+A/616/A173 : Rotational spectrum of ethyl isocyanate (Kolesnikova+, 2018)
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- J' Upper state J quantum number
4- 6 I3 --- Ka' Upper state Ka quantum number
7- 9 I3 --- Kc' Upper state Kc quantum number
10- 12 I3 --- J" Lower state J quantum number
13- 15 I3 --- Ka" Lower state Ka quantum number
16- 18 I3 --- Kc" Lower state Kc quantum number
23- 33 F11.4 MHz FreqObs Observed transition frequency
36- 42 F7.4 MHz O-C Observed minus calculated frequency
45- 50 F6.4 MHz e_FreqObs Experimental uncertainty
53- 59 F7.4 MHz (O-C)b ? Observed minus calculated frequency for
blends
61- 64 F4.2 --- wb ? Weight of the components of the blends
68-126 A59 --- Notes Vibrational state and the source
of the data (1)
--------------------------------------------------------------------------------
Note (1): Hirono et al., 1987, J. Mol. Struc., 162, 359.
--------------------------------------------------------------------------------
Acknowledgements:
Lucie Kolesnikova, lucie.kolesnikova(at)uva.es
(End) Lucie Kolesnikova [GEM, UVa, Spain], Patricia Vannier [CDS] 07-Nov-2018