Complex Organic Molecules Formation in Cold Cores on Stochastically Heated Grains

By Keith Cowing
Press Release
September 12, 2022
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Complex Organic Molecules Formation in Cold Cores on Stochastically Heated Grains
The temporal evolution of fractional ice composition on different sizes of grains in model M1. In this figure and the following figures, “g” stands for granular species.

We investigate the roles of stochastic grain heating in the formation of complex organic molecules (COMs) in cold cores, where COMs have been detected. Two different types of grain-size distributions are used in the chemical models.

The first one is the MRN distribution, and the second one considers grain coagulation to study its effects on the chemical evolution in these environments. The macroscopic Monte Carlo method is used to perform the two-phase chemical model simulations. We find that (1) grain coagulation can affect certain gas-phase species, such as CO2 and N2H+, in the cold core environments, which can be attributed to the volatile precursors originating from the small grains with temperature fluctuations; (2) grains with radii around 4.6 × 10−3 μm contribute most to the production of COMs on dust grains under cold core conditions, while few species can be formed on even smaller grains with radii less than 2 × 10−3 μm; (3) COMs formed on stochastically heated grains could help explain the observed abundances of gas-phase COMs in cold cores.

Long-Fei Chen, Qiang Chang, Yao Wang, Di Li

Comments: 15 pages, 10 figures, 3 tables. Accepted by MNRAS
Subjects: Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2209.05190 [astro-ph.GA] (or arXiv:2209.05190v1 [astro-ph.GA] for this version)
Submission history
From: Long-Fei Chen
[v1] Mon, 12 Sep 2022 12:30:00 UTC (1,632 KB)
full paper
Astrobiology, Astrochemistry

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