J/A+A/538/A51 Rotational spectrum of CH3CH(NH2)CN (Mollendal+, 2012)
Rotational spectrum of a chiral amino acid precursor, 2-aminopropionitrile,
and searches for it in Sagittarius B2(N).
Mollendal H., Margules L., Belloche A., Motiyenko R.A., Konovalov A.,
Menten K. M., Guillemin J.-C.
<Astron. Astrophys. 538, A51 (2012)>
=2012A&A...538A..51M 2012A&A...538A..51M
ADC_Keywords: Interstellar medium ; Spectroscopy
Keywords: astrochemistry - ISM: molecules - submillimeter: ISM -
line: identification - astronomical databases: miscellaneous -
ISM: individual objects: Sagittarius B2
Abstract:
No chiral molecule has been detected in the interstellar medium (ISM)
so far. A good candidate for an interstellar detection is
2-aminopropionitrile (CH3CH(NH2)CN), a chiral and the simplest
molecule with a C3H6N2 formula. The first member of this series,
aminoacetonitrile (H2NCH2CN), was recently detected, demonstrating
that at least one aminonitrile exist in the ISM. Experimental spectra
of 2-aminopropionitrile have been recorded in the microwave and sub-mm
energy range (8-80GHz, 150-660GHz).
An unbiased spectral survey of the 80-116GHz atmospheric window
performed with the IRAM 30m telescope is used to search for this
molecule in the hot core Sgr B2(N). This survey is analysed in the
local thermodynamical equilibrium (LTE) approximation. The emission of
2-aminopropionitrile is modeled simultaneously with the emission of
all molecules known in Sgr B2(N), which allows to properly take into
account line blending and avoid mis-assignments.
Only 10 groups of transitions of 2-aminopropionitrile are not severely
affected by line blending in the Sgr B2(N) spectrum. Six of them could
be considered as tentatively detected but the LTE predictions of the
four remaining groups are not (or only marginally) consistent with the
observed spectrum. Therefore, only an upper limit of 1.7*1016cm-2
can be securely derived for the column density of 2-aminopropionitrile
toward Sgr B2(N).
Description:
More than 4000 lines of the ground state and the 5 lowest excited
vibrational states (from 185 to 375cm-1) were assigned in the
experimental spectrum. The measured lines are listed in this table.
The molecule is an asymmetric top, the fits are performed with
Watson's A reduction and Ir representation
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 63 6194 Measured lines
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See Also:
J/A+A/538/A119 : 18O isotopic species of methyl formate data (Tercero+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- vt Vibrationnal state
7- 8 I2 --- J" [3/99] Upper J quantum number
11- 12 I2 --- Ka" [0/58] Upper Ka quantum number
15- 16 I2 --- Kc" [0/97] Upper Kc quantum number
21- 22 I2 --- J' [2/98] Lower J quantum number
25- 26 I2 --- Ka [0/58] Lower Ka quantum number
29- 30 I2 --- Kc' [0/96] Lower Kc quantum number
36- 46 F11.4 MHz Freq [20804/658562] Observed transition frequency
48 A1 --- n_Freq [B] B if lines are blended
50- 56 F7.4 MHz O-C Observed - Calculated frequencies
58- 63 F6.4 MHz e_O-C Uncertainty of measurements
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Acknowledgements:
Laurent Margules, laurent.margules(at)univ-lille1.fr
(End) Laurent Margules [Phlam, France], Patricia Vannier [CDS] 08-Dec-2011