Chemical and radiative transfer modeling of propylene oxide

Indian Centre for Space Physics, 43 Chalantika, Garia Station Road, Kolkata 700084, India
e-mail: ankan@csp.res.in

Received: 19 December 2018
Accepted: 10 June 2019

Abstract

Context. The recent identification of the first complex chiral molecule, propylene oxide (PrO), in space opens up a new window to further study the origin of homochirality on the Earth. There are some recent studies to explain the formation of PrO however additional studies on the formation of this species are needed for better understanding.

Aims. We seek to prepare a complete reaction network to study the formation of propylene oxide in the astrophysically relevant conditions. Based on our results, a detailed radiative transfer modeling has been carried out to propose some more transitions that would potentially be targeted in the millimeter wave domain.

Methods. A gas-grain chemical network was used to explain the observed abundance of PrO in a cold shell surrounding the high-mass star-forming region of Sgr B2. Quantum chemical calculations were employed to study various reaction parameters and to compute multiple vibrational frequencies of PrO.

Results. To model the formation of PrO in the observed region, we considered a dark cloud model. Additionally, we used a model to check the feasibility of forming PrO in the hot core region. Some potential transitions in the millimeter wave domain are predicted that could be useful for the future astronomical detection. We used radiative transfer modeling to extract the physical condition that might be useful to know the properties of the source in detail. Moreover, we provided vibrational transitions of PrO, which could be very useful for the future detection of PrO by the upcoming James Webb Space Telescope.