Europe's investment in galaxy research
The DAGAL (Detailed anatomy of galaxies) network ran from 2012 to 2016, explored the origin and evolution of the nearby Universe. The pan-European network of six academic partners enabled early-stage and experienced researchers to work collaboratively on a unique set of observations of over 2 300 nearby galaxies. To explore the structures and detailed properties of these galaxies, DAGAL fellows used multi-wavelength observations from space- and ground-based telescopes. Specifically, mid-infrared observations from the Spitzer space telescope were combined with ultraviolet, optical and radio data from a slew of other ground- and space-based telescopes. The Spitzer Survey of Stellar Structure in Galaxies (S4G) reaches unprecedented values of surface brightness over many spiral, elliptical and dwarf galaxies. S4G's wealth of data allowed the fellows to probe the stellar structure in the outskirts of galaxies, where gas and dark matter dominate over stars and test theoretical models of galaxy formation. The observations helped DAGAL researchers trace the motions of gas and stars and map the distribution of stellar mass and interstellar gas. This, in turn, supported numerical modelling efforts that were an integral part of the network's research. The theoretical predictions on the present structure of galaxies yielded fundamental constraints on how they had formed as well as how they will evolve in the future. Starting from stellar populations in the local group of galaxies to high-redshift systems, DAGAL improved our knowledge of the stellar, dust and gas content of galaxies. Their role in the interplay of galaxies and the intergalactic medium was also elucidated. The findings have been published in more than 100 papers. Moreover, the diversity of the DAGAL network in terms of expertise in galactic research offered unique opportunities for learning as well as professional development. During themed conferences coupled with workshops on professional development skills, fellows shared research experiences and collectively examined the framework underpinning their work.
Milky Way, galaxies, DAGAL, Spitzer space telescope, S4G