J/ApJ/853/139 1-(Z)-1-propanimine rotational transitions (Sil+, 2018)
Chemical modeling for predicting the abundances of certain aldimines and amines
in hot cores.
Sil M., Gorai P., Das A., Bhat B., Etim E.E., Chakrabarti S.K.
<Astrophys. J., 853, 139 (2018)>
=2018ApJ...853..139S 2018ApJ...853..139S
ADC_Keywords: Atomic physics; Interstellar medium
Keywords: astrochemistry ; dust, extinction ; evolution ; ISM: abundances ;
ISM: molecules ; methods: numerical
Abstract:
We consider six isomeric groups (CH3N, CH5N, C2H5N, C2H7N,
C3H7N, and C3H9N) to review the presence of amines and
aldimines within the interstellar medium (ISM). Each of these groups
contains at least one aldimine or amine. Methanimine (CH2NH) from
CH3N and methylamine (CH3NH2) from CH5N isomeric group were
detected a few decades ago. Recently, the presence of ethanimine
(CH3CHNH) from C2H5N isomeric group has been discovered in the
ISM. This prompted us to investigate the possibility of detecting any
aldimine or amine from the very next three isomeric groups in this
sequence: C2H7N, C3H7N, and C3H9N. We employ high-level
quantum chemical calculations to estimate accurate energies of all the
species. According to enthalpies of formation, optimized energies, and
expected intensity ratio, we found that ethylamine (precursor of
glycine) from C2H7N isomeric group, (1Z)-1-propanimine from
C3H7N isomeric group, and trimethylamine from C3H9N isomeric
group are the most viable candidates for the future astronomical
detection. Based on our quantum chemical calculations and from other
approximations (from prevailing similar types of reactions), a
complete set of reaction pathways to the synthesis of ethylamine and
(1Z)-1-propanimine is prepared. Moreover, a large gas-grain chemical
model is employed to study the presence of these species in the ISM.
Our modeling results suggest that ethylamine and (1Z)-1-propanimine
could efficiently be formed in hot-core regions and could be observed
with present astronomical facilities. Radiative transfer modeling is
also implemented to additionally aid their discovery in interstellar
space.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
propanimine.dat 75 53931 *Propanimine catalog
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Note on propanimine.dat: The catalog was generated as standard JPL format.
To prepare these catalog files, we used experimental rotational constants
values of 1-(Z)-1-propanimine and dipole moment components
(Margules+ 2015isms.confERI07M). Rotational transitions are generated for
1-(Z)-1-propanimine up to 650GHz for high temperature (T=200K).
Spectral intensities, along with the frequencies for rotational transitions
of 1-(Z)-1-propanimine in the millimeter and sub-millimeter regime predicted
by using the SPCAT program (Pickett 1991JMoSp.148..371P 1991JMoSp.148..371P).
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See also:
J/A+A/376/333 : Einstein A-coefficients for C3H4 (Sharma+, 2001)
J/ApJ/782/75 : Complete spectrum of methanol (Fortman+, 2014)
J/A+A/562/A56 : Cyanomethyl anion & deuterated derivatives (Majumdar+, 2014)
J/ApJ/795/56 : Experimental spectrum of methanol (CH3OH) (McMillan+, 2014)
J/ApJ/808/21 : Methyl acetate (CH3COOCH3) rotational transitions
(Das+, 2015)
Byte-by-byte Description of file: propanimine.dat
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Bytes Format Units Label Explanations
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3- 13 F11.4 MHz Freq [0.5/649805] Line frequency
16- 21 F6.4 MHz e_Freq [0] Estimated/experimental error in Freq
22- 29 F8.4 [nm2.MHz] logInt [-15/-2.6] log integrated intensity at 300K
31- 31 I1 --- DR [3] Degrees of freedom (1)
33- 41 F9.4 cm-1 ELo [-0/4078] Lower state energy (2)
42- 44 I3 --- GUp [1/343] Upper state degeneracy
47- 51 I5 --- TAG [57010] Species tag or molecular identifier
(always "57010" here) (3)
53- 55 I3 --- QNFMT [304] Format of the quantum numbers
(always "304")
56- 57 A2 --- J1 Upper state J quantum numbers
58- 59 A2 --- Ka1 Upper state Ka quantum numbers
60- 61 A2 --- Kc1 Upper state Kc quantum numbers
62- 63 A2 --- v1 Upper state v quantum numbers
68- 69 A2 --- J0 Lower state J quantum numbers
70- 71 A2 --- Ka0 Lower state Ka quantum numbers
72- 73 A2 --- Kc0 Lower state Kc quantum numbers
74- 75 A2 --- v0 Lower state v quantum numbers
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Note (1): 0 for atoms, 2 for linear molecules, and 3 for nonlinear molecules.
Note (2): Relative to the ground state.
Note (3): A negative value flags that the line frequency has been measured in
the laboratory. The absolute value of TAG is then the species tag and
ERR is the reported experimental error. The three most significant
digits of the species tag are coded as the mass number of the species.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-Oct-2018