The Supernova Origin of Interstellar Dust

摘要

Interstellar dust grains are prevalent in almost any astrophysical environment, and manifest their existence in many different ways. Yet, the origin and production rate of these grains are still uncertain. On page 196 of this issue, Sugerman and co-workers (1) take a hard look at the production of dust in massive supernovae, potentially the most important source of interstellar dust. Interstellar dust, consisting of small submicrometer-sized grains of predominantly silicateand carbonaceous composition, can be found in the interplanetary medium in our solar system; the gaseous nebulae around stars that have finished the normal hydrogen-burning part of their lives; and the general interstellar medium in normal galaxies likeour own, in extremely luminous galaxies undergoing intense star formation or harboring a massive black hole, as well as in very young galaxies at correspondingly large distances from the Milky Way. Even though interstellar dust constitutes less than 1% of the mass of the interstellar medium, it plays a crucial role in regulating its thermal energy balance, in catalyzing chemical reactions in molecular clouds, and in providing the basic building blocks for the formation of planetesimals in pro-toplanetary disks around main-sequence stars. In our Galaxy, the presence of dust grains is primarily inferred from their interaction with electromagnetic radiation, which gives rise to absorption, scattering, and polarization of Galactic starlight; infrared, submillimeter, and microwave emission, including the broad solid-state emission and absorption features; and the production of scattering halos around x-ray sources.