Unveiling the Secrets of Aromatic Hydrocarbons in Carbon-Rich Stars: A Journey into the Heart of Astrobiology
The Mystery of Aromatic Hydrocarbons Unveiled
In the vast cosmos, a captivating phenomenon unfolds within the envelopes of carbon-rich asymptotic giant branch (AGB) stars. Our research delves into the catalytic role of dust grains, revealing an intriguing pathway for the formation of aromatic hydrocarbons.
Unraveling the Chemical Mystery
We present a groundbreaking astrochemical model, a comprehensive tool that unites gas-phase, gas-surface, and surface reactions with the physical evolution of dust grains. This model, an enhancement of previous networks, incorporates updated reactions involving hydrocarbons up to pyrene.
Simulating Stellar Evolution
Our model simulates the chemical evolution of the envelope of IRC+10216, a prototypical AGB star. By comparing scenarios with and without the cyclotrimerization reaction, and varying the desorption energy of hydrocarbons, we uncover a significant impact on the abundance of aromatic species.
The Power of Surface Chemistry
Surface-catalyzed cyclotrimerization emerges as a pivotal process, enhancing the total abundance of aromatics by up to tenfold. This finding highlights the intricate link between gas-phase chemistry and dust surface processes, emphasizing the need for self-consistent modeling.
A Call for Accurate Modeling
Our work underscores the importance of constraining uncertain parameters, particularly desorption energies, for realistic astrochemical modeling of evolved stellar systems. This research opens new avenues for understanding the complex chemistry of the cosmos.
But here's where it gets controversial... Should we prioritize refining these parameters or focus on developing more comprehensive models? Your thoughts are welcome in the comments!
Authors: M. S. Murga, I. V. Loginov, D. S. Wiebe, D. R. Fedotova, V. S. Krasnoukhov, I. O. Antonov
Comments: Accepted to A&A. 14 pages, 6 figures
Subjects: Astrophysics of Galaxies, Solar and Stellar Astrophysics
Cite as: arXiv:2512.06510 [astro-ph.GA]
DOI: https://doi.org/10.48550/arXiv.2512.06510
Related DOI: https://doi.org/10.1051/0004-6361/202557089
