Suggestion for search of ethylene oxide (\(c\)-C2H4O) in a cosmic object

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Abstract

Ethylene oxide (\(c\)-C2H4O) and its isomer acetaldehyde (CH3CHO) are important organic molecules because of their potential role in the formation of amino acids. The \(c\)-C2H4O molecule is a \(b\)-type asymmetric top molecule and owing to half-spin of each of the four hydrogen atoms, it has two distinct ortho (nuclear spin one) and para (nuclear spin zero and two) species. It has been detected in the Sgr B2N. Using the rotational and centrifugal distortion constants along with the electric dipole moment, we have calculated energies of 100 rotational levels of each of the ortho and para species of \(c\)-C2H4O molecule and the Einstein \(A\)-coefficients for radiative transitions between the levels. The values of Einstein \(A\)-coefficients along with the scaled values for the collisional rate coefficients are used for solving a set of statistical equilibrium equations coupled with the equations of radiative transfer.

Brightness-temperatures of five rotational transitions of each of the ortho and para species of \(c\)-C2H4O molecule are investigated. Out of these ten transitions, three transitions are found to show the anomalous absorption and rest seven are found to show the emission feature. We have also investigated seven transitions observed unblended in the Sgr B2(N). We have found that the transitions \(3_{3 0} - 3_{2 1}\) (23.134 GHz), \(2_{2 0} - 2_{1 1}\) (15.603 GHz), \(3_{3 1} - 3_{2 2}\) (39.680 GHz) and \(1_{1 1} - 0_{0 0}\) (39.582 GHz) may play important role for the identification of ethylene oxide in a cosmic object.

Keywords

ISM: molecules Ethylene oxide Einstein \(A\)-coefficients Radiative transfer 

Notes

Acknowledgements

We are thankful to the learned reviewer for constructive and encouraging comments and to Prof. Z. Kisiel for valuable cooperation. We are grateful to Hon’ble Dr. Ashok K. Chauhan, Founder President and Hon’ble Chancellor Dr. Atul Chauhan, Amity University for valuable support and encouragement. Thanks are due to Dr. Pramod G. Musrif for the optimization of molecule. MKS is thankful to the SERB, DST, New Delhi for financial support in the form of NPDF.

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© Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  1. 1.Amity Centre for Astronomy & Astrophysics, Amity Institute of Applied SciencesAmity UniversityNoidaIndia
  2. 2.School of Studies in PhysicsJiwaji UniversityGwaliorIndia

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