Graphene Oxide Nanoparticles in the Interstellar Medium

TL;DR

This paper proposes that graphene oxide nanoparticles are a significant component of interstellar dust and are likely responsible for the Extended Red Emission observed in space, supported by laboratory and infrared observations.

Contribution

It introduces the novel idea that graphene oxide nanoparticles cause the ERE in interstellar medium, linking laboratory spectra with astronomical observations.

Findings

Laboratory spectra of graphene oxide match ERE features.

Infrared emissions support the presence of graphene oxide in space.

Graphene oxide nanoparticles are proposed as a major dust component.

Abstract

Dust particles play a major role in the formation, evolution and chemistry of interstellar clouds, stars and planetary systems. Commonly identified forms include amorphous and crystalline carbon-rich particles and silicates. Also present in many astrophysical environments are polycyclic aromatic hydrocarbons (PAHs), detected through their infrared emission, and which are essentially small flakes of graphene. Astronomical observations over the past four decades have revealed a widespread unassigned Extended Red Emission (ERE) feature which is attributed to luminescence of dust grains. Numerous potential carriers for ERE have been proposed but none has gained general acceptance. In this Letter it is shown that there is a strong similarity between laboratory optical emission spectra of graphene oxide and ERE, leading to this proposal that emission from graphene oxide nanoparticles is the origin of ERE and that these are a significant component of interstellar dust. The proposal is supported by infrared emission features detected by the Infrared Space Observatory (ISO) and the Spitzer Space Telescope.