After more than two decades of infrared astronomy, we still know very little about the origin and evolution of cosmic dust in galaxies, responsible for obscuring half of all starlight since the Big Bang. This obscured starlight is re-radiated in a region of the electromagnetic spectrum that is still relatively unexplored. Our view of the universe has been biased: we lack vital knowledge about the origin of cosmic dust, its evolution, and therefore the fuel for star formation of galaxies over recent cosmic history. The Herschel Space Observatory provides a unique opportunity to resolve this by revealing the 90% of dust too cold to be detected before, yet only a tiny fraction of the largest survey of the sky carried out with Herschel has been exploited.
This project will produce the first statistical census of cosmic dust in galaxies, the raw material of rocky planets and building blocks for life, and provide key insights into the quantity and properties of dust formed in exploding stars using datasets, tools and techniques that our group has developed, tested and has unique access to. Dust contains roughly half the heavy elements in the interstellar medium today, up to 70% at early epochs [77], and is responsible for obscuring almost half of the energy emitted by stars since the Big Bang. This light is re-emitted in the infrared (IR) and submillimetre (submm) regime, a region of the electromagnetic spectrum that was, until recently, relatively unexplored. After more than two decades of space-based IR astronomy, we arguably still know very little about the local Universe at these wavelengths. We lack vital knowledge about the evolution of the dust and gas content and therefore the fuel for star formation of galaxies over recent cosmic history; furthermore, the long-standing controversy over the origin of cosmic dust is still unsolved. Consequently, we cannot even begin to match our understanding of the visible universe with the little information we have on obscured, dusty galaxies over cosmic time.
CosmicDust aims to build the largest catalogue of dusty galaxies (a ‘census' of dust) and help uncover mysterious new classes of galaxies that appear dust-poor in visible light images, but actually contain huge quantities of dust. This project will ensure the the full potential of Herschel is realised, well in advance of the next generation of space telescopes.
