Potential spectral lines of ethanimine (CH[formula omitted]CHNH) - an important possible precursor of amino acids

Abstract

Accurate computational characterization of ethanimine (CH3NH), considered as an important possible precursor of amino acids, is now available. Ethanimine has two E and Z isomers and each isomer has two A and E substates. Some lines of Green Bank Telescope PRIMOS radio astronomy survey spectra in Sagittarius B2 North (Sgr B2(N)) have been assigned to the ethanimine. For known values of accurate energies of rotational levels in the ground vibrational state, and the spectroscopic data (rotational and centrifugal distortion constants, and electric dipole moment), we have calculated Einstein A and B coefficients (radiative transition probabilities) for rotational transitions for each substate. These radiative transition probabilities along with collisional rate coefficients are calculated using a scaling law have been used for solving a set of statistical equilibrium equations coupled with the equations of radiative transfer for each substate. We have found a number of weak MASER lines and anomalous absorption lines for each substate. These lines may play important role for identification of ethanimine in a cosmic object. Corresponding lines in two substates in a isomer have been found to show similar behaviour, except different values of their frequencies.