„ASTROdust: a complete census of dust attenuation in galaxies based on the analysis of millions of galaxies observed by Herschel” is the project SONATA BIS 2018/30/E/ST9/00082 (founded by National Science Centre, Poland). 

PI: Katarzyna Małek
Link: ASTROdust project


Stars are seldom found alone in the universe. They are formed and live out their lives together with other stars in massive associations known as galaxies. Optical telescopes show that our Universe if full of such islands. But the visible light is not the best source of information about galaxies and the structures inside them. Massive stars can emit in visible wavelengths such amount of energy that they seem to be disproportionally more significant than they really are. In the infrared this imbalance is less extreme, so we can get a more representative view of how the structure of the galaxy looks like, and how stars are actually distributed. Additionally, many galaxies are also filled with dust clouds that obscure our view of the overall structure of the galaxy. But thanks to the characteristic of dust, which become more transparent towards longer wavelengths, and is some ranges – it re-emits the ultraviolet light emits by young stars, galaxies observed in infrared light shows all the inaccessible in visible light structures of the galaxy. All those reasons cause that observation of galaxies in infrared range allows uncovering of areas inaccessible for optical observations.

The main aim of the project is to statistically investigate the attenuation of dust in galaxies and its dependence on the types of galaxies in different space ages. We will use a unique sample of one million galaxies observed in the infrared by the Herschel satellite. We plan to construct the correct attenuation curves for different types of galaxies and to examine how they have evolved over the past 10 billion years. This will lead to a re-evaluation of the basic physical properties of star-forming galaxies and will provide new tools to astronomers who occupy themselves with these fascinating objects.