Unexplained Spectral Phenomena in the Interstellar Medium: an introduction

TL;DR

This paper introduces the mystery surrounding various unidentified spectral features in the interstellar medium, highlighting their potential organic origins and the challenge they pose to understanding cosmic chemical synthesis.

Contribution

It provides an overview of unexplained spectral phenomena in space and discusses their possible organic chemical origins, emphasizing the need for further research.

Findings

Multiple unidentified spectral features observed in diverse environments

Potential organic chemical compounds as their origin

Highlights the challenge in understanding cosmic organic synthesis

Abstract

There exists a number of astronomical spectral phenomena that have remained unidentified after decades of extensive observations. The diffuse interstellar bands, the 220 nm feature, unidentified infrared emission bands, extended red emissions, and 21 and 30 $\mu$m emission features are seen in a wide variety of astrophysical environments. The strengths of these features suggest that they originate from chemical compounds made of common elements, possibly organic in nature. The quest to understand how such organic materials are synthesized and distributed across the Galaxy represents a major challenge to our understanding of the chemical content of the Universe.