Final Report Summary - DUSTYGAL (The formation of massive galaxies: the roles of dust-obscured starbursts and AGN activity)
The DUSTYGAL programme was undertaken by an international team of early-stage researchers who investigated the properties and nature of an enigmatic population of very luminous, but very dusty galaxies in the early Universe. The programme was launched at the start of operations of the new €1.2B Atacama Large Millimetre Array (ALMA) and the team led the first large study of the dusty galaxy population with this new facility, uncovering a wealth of new information about the formation and evolution of these galaxies. Using their ALMA surveys, the DUSTYGAL team showed that a fraction of these systems are so dusty and so distant that they are invisible in even the deepest observations with the Hubble Space Telescope and thus they were completely missed by existing censuses of the star-formation history of the Universe. The team discovered that most of these galaxies are powered by intense starbursts, with only a small proportion showing evidence for significant contributions to their emission from supermassive black holes. DUSTYGAL demonstrated that these starbursts are occurring in a relatively brief period in the history of the Universe, between 9 and 11 billion years ago, that they are associated with massive galaxies and are likely associated with the formation of the oldest components of galaxies seen at the present day: bulges. This answers a twenty year puzzle about the nature of these galaxies which had existed since their discovery in the late 1990s.