Til bevillingsoversigt

Physical pRoperties of the InterStellar Medium in Luminous Infrared Galaxies at High redshifT

Carlsberg Foundation Reintegration Fellowships

What

Most of the stars we see in local galaxies were formed more than 10 billion years ago at a time when galaxies appeared radically different. How these early galaxies formed and evolved into the galaxies in the local universe is still not well understood. The key to establishing this is to understand how the building blocks of the galaxies (i.e. gas, dust and stars) interact and evolve. This project will provide insight into the evolution of galaxies by measuring some of their key physical parameters: dynamical masses, metallicities and molecular gas masses, for a sample of galaxies not subject to previous selection biases e.g. how fast stars are formed and black hole activity. These measurements will help reveal how stars are formed in both rapidly evolving and more passive environments.

Why

The rate of production of stars throughout the history of the Universe has not been constant. From the formation of the first galaxies 13 billion years ago, the rate of cosmic star-formation increased, peaking around 10 billion years ago, and has been steadily decreasing since. This evolution in the star formation history, suggest that stars in local and distant galaxies formed under different conditions. Theories and models describing star-formation processes within local galaxies, are often applied to rapidly evolving distant galaxies. It is unclear, however, if these models accurately describe the internal properties in distant galaxies. This project will provide insight into what drives star-formation in distant galaxies, and the differences between local and distant galaxies.

How

I have been awarded observing time on the Very Large Telescope (at ESO) to obtain data which will allow me to measure the internal processes such as rotation and metallicity of a sample of distant galaxies. These processes are believed to be key in the formation of stars in distant galaxies. The molecular gas phase is the birthplace of stars and measurements of the molecular gas masses are therefore crucial in order to establish the amount of cold gas available for star-formation. However, such measurements are highly uncertain for distant galaxies. These observations will help improve how we determine the molecular gas mass and how this is dependent on for example the metallicity. This project will shed new light on the conditions stars are formed under in distant galaxies.

SSR

Astronomy is a popular subject with the public, due to the detailed and colourful images of, for example, planets, local star-forming nebulae and galaxies, and the fascination of understanding the origin of 'us' and our world. However, popular interest in distant galaxies has been limited due to low-resolution images, in which they appear as "fuzzy blobs". With this project we are moving towards seeing distant galaxies with detail on scales comparable to that of local galaxies, and will show the importance of Denmark's engagement in scientific flagships such as the European Southern Observatory. This project will cement Danish leadership of an international team using world class observatories to understand how galaxies evolve. This project will offer a unique opportunity to increase the curiosity and knowledge of distant galaxies and help spark an enhanced interest in astronomy, as well as in STEM subjects in general.