Modeling Complex Organic Molecules’ Formation in Cold Cores: Multiphase Models with Nonthermal Mechanisms
Year: 2025
Type: article
Abstract: In recent years, a significant number of oxygen-bearing complex organic molecules (COMs) have been detected in the gas phase of cold dark clouds such as TMC-1. The formation of these COMs cannot be explained by diffusive mechanisms on grains and gas-phase reactions. This study investigates the formation of oxygen-bearing COMs in cold dark clouds using multiphase gas–grain models that incorporate cosmic ray-induced nondiffusive radiation chemistry and nonthermal sputtering desorption mechanisms. Additionally, we present the effects of varying elemental C/O ratio and different sputtering rates. We utilized an accelerated Gillespie algorithm, based on the regular Gillespie algorithm. The results of our models for dimethyl ether (CH3OCH3), methyl formate (HCOOCH3), acetaldehyde (CH3CHO), ethanol (C2H5OH), and methanol (CH3OH) show reasonable agreement with observations toward TMC-1, within a factor of 3. Out of the 94 species compared with observations, 63 show agreement within 1 order of magnitude, accounting for 67.02%. Overall inclusion of nonthermal mechanisms in multiphase models shows notable improvement of modeling on oxygen-bearing COMs in the interstellar medium.
Authors: Yang Lu, Donghui Quan, Qiang Chang, Long-Fei Chen, Di Li
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Award: G2275397869
OpenAlex ID: W4407712570