J/A+A/657/A99 The rotational spectrum of glycinamide (Kisiel+, 2022)
Millimetre-wave laboratory study of glycinamide and search for it
with ALMA toward Sagittarius B2(N).
Kisiel Z., Kolesnikova L., Belloche A., Guillemin J.-C., Pszczolkowski L.,
Alonso E.R., Garrod R.T., Bialkowska-Jaworska E., Leon I., Mueller H.S.P.,
Menten K.M., Alonso J.L.
<Astron. Astrophys. 657, A99 (2022)>
=2022A&A...657A..99K 2022A&A...657A..99K (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Spectroscopy ; Atomic physics
Keywords: astrochemistry - ISM: molecules -
astronomical databases: miscellaneous -
ISM: individual objects: Sagittarius B2 - line: identification
Abstract:
Glycinamide (NH2CH2C(O)NH2) is considered to be one of the
possible precursors of the simplest amino acid glycine. Its only
rotational spectrum reported so far has been in the cm-wave region on
a laser-ablation generated supersonic expansion sample.
The aim of this work is to extend the laboratory spectrum of
glycinamide into the millimetre wave region to support its searches in
the interstellar medium and to perform the first check for its
presence in the high-mass star forming region Sagittarius B2(N).
Glycinamide was synthesised chemically and was studied with broadband
rotational spectroscopy in the 90-329 GHz region with the sample in
slow flow at 50°C. Tunneling across a low energy barrier between two
symmetry equivalent configurations of the molecule resulted in
splitting of each vibrational state and many perturbations in
associated rotational energy levels, requiring careful coupled state
fits for each vibrational doublet. We searched for emission of
glycinamide in the imaging spectral line survey ReMoCA performed with
the Atacama Large Millimetre/submillimetre Array toward Sgr B2(N). The
astronomical spectra were analysed under the assumption of local
thermodynamic equilibrium.
We report the first analysis of the mm-wave rotational spectrum of
glycinamide, resulting in fitting to experimental measurement accuracy
of over 1200 assigned and measured transition frequencies for the
ground state tunneling doublet, of many lines for tunneling doublets
for two singly excited vibrational states, and determination of
precise vibrational separation in each doublet. We did not detect
emission from glycinamide in the hot molecular core Sgr B2(N1S). We
derived a column density upper limit of 1.5x1016cm-2, which
implies that glycinamide is at least seven times less abundant than
aminoacetonitrile and 1.8 times less abundant than urea in this
source.
Description:
Observed rotational transitions of glycinamide in the ground state and
two excited state tunneling doublets
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table5.dat 119 1400 Fitted rotational transitions of glycinamide
in the ground state (0+ 0- doublet)
table6.dat 80 990 Fitted rotational transitions of glycinamide
in v27=1 state (1+ 1- doublet)
table7.dat 80 781 Fitted rotational transitions of glycinamide
in v26=1 state (0+ 0- doublet)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.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 --- v' Upper state v quantum number (1)
15- 17 I3 --- J" Lower state J quantum number
18- 20 I3 --- Ka" Lower state Ka quantum number
21- 23 I3 --- Kc" Lower state Kc quantum number
24- 26 I3 --- v" Lower state v quantum number (1)
40- 50 F11.4 MHz FreqObs Observed transition frequency
53- 59 F7.4 MHz O-C Observed minus calculated frequency
62- 66 F5.3 MHz FreqExp Experimental uncertainty
69- 75 F7.4 MHz (O-C)b ? Observed minus calculated frequency for blends
77- 80 F4.2 --- wb ? Weight of the components of the blends
85-119 A35 --- Source Source of the data
--------------------------------------------------------------------------------
Note (1): The vibrational quantum number v=0 corresponds to 0+ state and
v=1 to 0- state of the ground state tunneling doublet.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.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 --- v' Upper state v quantum number (1)
15- 17 I3 --- J" Lower state J quantum number
18- 20 I3 --- Ka" Lower state Ka quantum number
21- 23 I3 --- Kc" Lower state Kc quantum number
24- 26 I3 --- v" Lower state v quantum number (1)
40- 50 F11.4 MHz FreqObs Observed transition frequency
53- 59 F7.4 MHz O-C Observed minus calculated frequency
62- 66 F5.3 MHz FreqExp Experimental uncertainty
69- 75 F7.4 MHz (O-C)b ? Observed minus calculated frequency for blends
77- 80 F4.2 --- wb ? Weight of the components of the blends
--------------------------------------------------------------------------------
Note (1): The vibrational quantum number v=0 corresponds to 1+ state and
v=1 to 1- state of the v27=1 tunneling doublet.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.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 --- v' Upper state v quantum number (1)
15- 17 I3 --- J" Lower state J quantum number
18- 20 I3 --- Ka" Lower state Ka quantum number
21- 23 I3 --- Kc" Lower state Kc quantum number
24- 26 I3 --- v" Lower state v quantum number (1)
40- 50 F11.4 MHz FreqObs Observed transition frequency
53- 59 F7.4 MHz O-C Observed minus calculated frequency
62- 66 F5.3 MHz FreqExp Experimental uncertainty
69- 75 F7.4 MHz (O-C)b ? Observed minus calculated frequency for blends
77- 80 F4.2 --- wb ? Weight of the components of the blends
--------------------------------------------------------------------------------
Note (1): The vibrational quantum number v=0 corresponds to 0+ state and
v=1 to 0- state of the v26=1 tunneling doublet.
--------------------------------------------------------------------------------
Acknowledgements:
Zbigniew Kisiel, kisiel(at)ifpan.edu.pl
(End) Z. Kisiel [IFPAN, Warszawa, Poland], P. Vannier [CDS] 29-Dec-2021