In Dust We Trust: An Overview of Observations and Theories of Interstellar Dust

TL;DR

This review summarizes the historical development, observational evidence, and current understanding of interstellar dust's physical and chemical properties, highlighting its role in galactic evolution and star formation.

Contribution

It provides a comprehensive overview of observational and theoretical advances in interstellar dust research, including unresolved challenges.

Findings

Interstellar dust is crucial in galaxy evolution and star formation.

Observational evidence includes extinction, emission, and polarization data.

Current models explain dust formation and modification processes.

Abstract

The past century of interstellar dust has brought us from first ignoring it to finding that it is an important component of the interstellar medium and plays an important role in the evolution of galaxies, the formation of stars and planetary systems, and possibly, the origins of life. Current observational results in our galaxy provide a complex physical and chemical evolutionary picture of interstellar dust starting with the formation of small refractory particles in stellar atmospheres to their modification in diffuse and molecular clouds and ultimately to their contribution to star forming regions. In this review, a brief history of the studies of interstellar dust is presented. Our current understanding of the physical and chemical properties of interstellar dust are summarized, based on observational evidences from interstellar extinction, absorption, scattering, polarization, emission (luminescence, infrared vibrational emission, and microwave rotational emission), interstellar depletions, and theoretical modelling. Some unsolved outstanding problems are listed.