Classifying Protoplanetary Disk Infrared Spectra For Possible Templates For Biological Molecules

By Keith Cowing
Status Report
March 12, 2023
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Classifying Protoplanetary Disk Infrared Spectra For Possible Templates For Biological Molecules

Protoplanetary disk around a just born young star contains a lot of cosmic dust. especially polycyclic-aromatic-hydrocarbon (PAH), which would become basic component to create biological organics.

This study classified many astronomically observed infrared spectra of protoplanetary disks to three typical spectra. Type-A show well known astronomical bands of 6.2, 7.8, 8.6 and 11.3 micrometer.

Whereas Type-B included unknown complex bands. Type-(A+B) was their mixed type. We tried to find specific molecule by Density Functional Theory (DFT) calculation. We found that Type-A could be explained by large PAH molecules of (C23H12) and (C53H18), which are hexagon-pentagon combined molecular structure.

Background molecule of Type-B was smaller ones of (c-C3H2), (C5H5), (C9H7) and (C12H8). Type-(A+B) was reproduced well by mixing those molecules of A and B. Astronomical detailed observation shows that central star of Type-A has larger mass and higher temperature than that of Type-B. This suggests that at very early stage of our solar system, our protoplanetary disk had been made up by Type-B molecules.

It was interesting that (C5H5) and (C9H7) of Type-B molecules has similar molecular structure with biological nucleic-acid on our earth. Type-B molecules was supposed to become the template for synthesizing biological organics and finally for creating our life.

Classifying Protoplanetary disks Infrared Spectrum and Analysis by c-C3H2 C5H5 C9H7 C12H8 C23H12 and C53H18 to be Capable Template for Biological Molecule

Norio Ota, Aigen Li

Comments: 10 pages, 20 figures, 1 table, 27 references
Subjects: Astrophysics of Galaxies (astro-ph.GA); Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR); Atomic and Molecular Clusters (physics.atm-clus)
Cite as: arXiv:2303.05645 [astro-ph.GA] (or arXiv:2303.05645v1 [astro-ph.GA] for this version)
Submission history
From: Norio Ota
[v1] Fri, 10 Mar 2023 01:32:10 UTC (1,394 KB)
Astrobiology, Astrochemistry

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻