Modeling c2h4o2 isomers in cold dark clouds

Paulive, Alec

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https://hdl.handle.net/2142/107319 Copy

Description

Title

Modeling c2h4o2 isomers in cold dark clouds

Author(s)

Paulive, Alec

Contributor(s)

Herbst, Eric

Issue Date

2020-06-23

Keyword(s)

Astronomy

Abstract

Complex organic molecules (COMs) have been detected in a variety of interstellar sources. These sources allow for methods of production linked to increasing temperatures and densities, allowing for thermal chemical reactions to occur rapidly enough to produce observable amounts of COMs, both in the gas phase, and upon dust grains, which then become gaseous as the temperature increases to sublimate the COMs off the grain. As more precursor molecules are detected in colder regions of interstellar space such as cold dark clouds, the same thermal methods of COM production are not efficient enough to produce observable amounts. Radiolysis chemistry is a possible non-thermal method of producing observable amounts of COMs in cold dark clouds. This new method greatly increases the modeled abundance of COMs upon the ice surface and within the ice mantle due to excitation and ionization events from cosmic ray bombardment. We examine three C$_{2}$H$_{4}$O$_{2}$ isomers, and a chemically similar molecule, dimethyl ether (CH$_3$OCH$_3$). The modeled abundances of methyl formate (HCOOCH$_3$) and glycolaldehyde (HCOCH$_2$OH) should be in the observable range, with fractional abundances of approximately $3.0 \times 10^{-11}$ and $1.3 \times 10^{-11}$, respectively, with respect to hydrogen. Acetic acid (CH$_3$COOH) is greatly enhanced with the inclusion of radiolysis, with a modeled fractional abundance of $1.375 \times 10^{-13}$, but is not at observable abundances. Dimethyl ether, while detected in these regions is not greatly enhanced by radiolysis chemistry, with models with and without radiolysis chemistry show gas-phase fractional abundances of $2.5 \times 10^{-10}$ and $2.4 \times 10^{-10}$, respectively.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/107319

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Copyright 2020 is held by the Author(s)

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