Void induced molecule c23h12++ could reproduce the infrared spectrum (3 to 20 micron) of interstellar gas and dust

TL;DR

This study demonstrates that the void-induced cation C23H12++ can accurately reproduce the infrared spectrum of interstellar gas and dust, suggesting a specific PAH molecule may dominate in space.

Contribution

The paper introduces a specific void-induced PAH molecule, C23H12++, as a new candidate capable of matching observed interstellar infrared spectra, highlighting its unique structure and spectral properties.

Findings

C23H12++ reproduces key infrared emission peaks.

The molecule's structure is significantly deformed by Jahn-Teller effect.

A single molecule can account for multiple observed spectral features.

Abstract

In order to find out a selected number of molecules to reproduce the infrared spectrum of interstellar gas and dust, model coronene molecules with void and charge have been computed using density functional theory. Among them, a single void induced cation C23H12++ have successfully reproduced a wide range spectrum from 3 to 20 micron of typical interstellar gas and dust. Well known astronoically observed emission peaks are 3.3, 6.2, 7.6, 7.8, 8.6, 11.2, 12.7, 13.5 and 14.3 micro meter. Whereas, calculated peaks of C23H12++ were 3.2, 6.4, 7.6, 7.8, 8.6, 11.4, 12.9, 13.5, and 14.4 micron meter. It should be noted that a single kind of molecule could reproduce very well not depending on the decomposition method using many polycyclic aromatic hydrocarbon (PAH) data. Such coincidence suggested that some astronomical chemical evolution may select a particular PAH. Molecular sructure of C23H12++ was dramatically deformed by the Jahn-Teller effect. There is a featured carbon skeleton having two pentagons connected to highly symmetrical five hexagons. Such unique structure brings above infrared mode.