Hydrocarbon Emission in Galaxies: A Systematic Study
Published:Dec 25, 2025 13:35
•1 min read
•ArXiv
Analysis
This paper investigates the processing of hydrocarbon dust in galaxies, focusing on the ratio of aliphatic to aromatic hydrocarbon emission. It uses AKARI near-infrared spectra to analyze a large sample of galaxies, including (U)LIRGs, IRGs, and sub-IRGs, and compares them to Galactic HII regions. The study aims to understand how factors like UV radiation and galactic nuclei influence the observed emission features.
Key Takeaways
- •The study uses AKARI near-infrared spectra to analyze hydrocarbon emission in a large sample of galaxies.
- •The ratio of aliphatic to aromatic hydrocarbon emission varies significantly across different galaxy types.
- •The $L_{ali}/L_{aro}$ ratio is correlated with factors like total infrared luminosity ($L_{IR}$) and the HI recombination line Brα.
- •Continuum colors at 4 um can indicate the processing of PAHs by UV radiation or the presence of obscured galactic nuclei.
Reference
“The luminosity ratios of aliphatic to aromatic hydrocarbons ($L_{ali}/L_{aro}$) in the sample galaxies show considerably large variations, systematically decreasing with $L_{IR}$ and $L_{Brα}$.”