In order to address the general goal of this Project, we are working with the most comprehensive infrared galaxy survey ever conducted with the Spitzer Space Telescope for the study of the early Universe (Spitzer Exploration Science Programme SMUVS - PI K. Caputi). The unprecedented characteristics of this survey, which has obtained deep infrared images over a relatively large area of the sky, are allowing us to study 66,000 galaxies present in the Universe in the first few billions years of cosmic time. Our main results in the BUILDUP Project so far can be summarised as follows.
1) We have discovered a new population of intense star-forming galaxies when the Universe was only 1.5 billion years old, i.e. about 10% of its present age. Although in number these galaxies were only a small percentage of all galaxies in the Universe, their individual star formation rates were so high that they were making altogether more than a half of all the stars being formed in the Universe at those cosmic times.
2) We have found that there are fundamental differences in the evolution of large and small galaxies in the young Universe. This refers to the way in which they form their stars, as well as how star formation eventually declines to make galaxies become quiescent.
3) We have quantitatively proved, for the first time, the large-scale structure traced by galaxies when the Universe was only a few billion years old. The early onset of galaxy large-scale structure is one of the key predictions of the most accepted cosmological model, which is the Lambda cold dark matter model.
In addition, we are conducting simulations to prepare for the scientific exploitation of the galaxy surveys that we will conduct with the forthcoming James Webb Space Telescope (JWST). This will be one of the most important telescopes operating next decade and is expected to revolutionise our view of the early Universe. With our ongoing work, we the BUILDUP Team are positioning ourselves as leaders for the analysis of JWST data.
Update at the end of the Project: The JWST has been successfully launched in December 2021. Indeed my research group is in a leading position to scientifically exploit its observations, which will start in the second half of 2022. Although my ERC CoG is over, the PI Caputi has secured a new big grant (1.5 MEUR) from the Dutch Research Council NWO to work on high-z galaxy studies with JWST data. This new Project will leverage all our work done during the ERC CoG period.
