Zoomed-in maps of the system at t = tff+10 kyr (top) and t = tff + 150 kyr (bottom). The colors represent the number density of the gas, while the white lines indicate the iso-contours of the temperature at T= 50, 75, 100, and 300 K. — astro-ph.GA
Complex organic molecules (COMs) are thought to be the precursors of pre-biotic molecules and are observed in many protostellar sources.
For this paper we studied the formation of COMs during star formation and their evolution in the midplane of the circumstellar disk up to the end of the Class I stage. We used the Analytical Protostellar Environment (APE) code to perform analytical simulations of star formation and the Nautilus code to model the chemical evolution.
Most COMs mainly form during the collapse or in the disk, except the lightest (CH3CCH, C3H6, CH3OH, CH3CHO, CH3OCH3, C2H5OH, CH3CN, CH3NC, C2H3CN, and CH3SH), which are significantly inherited by the disk from the prestellar phase.
Over the first 150 kyr of the disk, the abundances of several COMs in the midplane vary negligibly (e.g., CH3CCH, CH3OH, and CH3CN), while others experience a variation of one order of magnitude (e.g., C2H3CHO HOCH2CHO, and CH3COCH2OH). Changing physical conditions also have an impact on the abundance profiles of COMs in the disk, and their inheritance.
For example, increasing the temperature of the molecular cloud from 10 K to 15 K significantly promotes the formation of COMs in the prestellar phase, notably c-C2H4O and N-bearing species. Conversely, increasing the cloud mass from 2 Msol to 5 Msol only has a minor effect on the disk abundances in the early stages.
Pierre Marchand, Audrey Coutens, Jean-Christophe Loison, Valentine Wakelam, Antoine Espagnet, Fernando Cruz-Sáenz de Miera
Comments: Accepted for publication in A&A
Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2509.15126 [astro-ph.GA] (or arXiv:2509.15126v1 [astro-ph.GA] for this version)
https://doi.org/10.48550/arXiv.2509.15126
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Submission history
From: Pierre Marchand
[v1] Thu, 18 Sep 2025 16:34:54 UTC (4,572 KB)
https://arxiv.org/abs/2509.15126
Astrobiology,