The Millennium Nucleus ERIS (Evolutionary Reconstruction of the InterStellar medium) will apply one of the principles of Darwin’s Theory of Evolution – descent with modification – to cosmic evolution and is lead by Paula Jofre (Director) and Evelyn Johnston (PI) from AstroUDP, together with Patricia Tissera (co-director) and Alvaro Rojas (PI) from Universidad Católica.

The fundamental tool (phylogenetic tree) is already extensively used in other evolutionary studies on Earth. Since trees are mathematical structures and graphs, with ERIS we will consolidate an interdisciplinary collaboration between astronomers, biologists and mathematicians, in order to achieve our scientific goals. We will reconstruct the evolution of galaxies by building and interpreting phylogenetic trees that are appropriate for astronomical data. To do so, we will simulate the evolution of galaxies, where we know their shared history. We will also use observed data, which will allow us to learn to deal with uncertainties.

The key to connect stars with one another is the well known fact that massive stars synthesize chemical elements in their interiors, and at the end of their lives, by exploding they pollute the interstellar clouds from which new stars form. Chemically processed gas is what one generation of stars inherit from the previous one(s) and are the key observable for us to build the phylogenetic trees. Our strength is the fact that we know very robustly what elements are produced in which type of stars, and how much of them. The challenge is the fact that a galaxy is an open system: fresh gas comes from outside all the time, diluting the existing one. Also, different generations of stars contribute to the pollution of the same interstellar clouds. Therefore, the problem is manifold and intricate, just like the biological evolution of species.

YEMS

The Millennium Nucleus on Young Exoplanets and their Moons (YEMS) will address the dichotomy in giant planet formation by developing new methods of young exoplanet detection, lead by Alice Zurlo (co-director) and Lucas Cieza (PI) from  AstroUDP,  together with Sebastian Perez (Director) and Fernando Rannou (PI) from Universidad Santiago, Guillermo Cabrera (PI)  from Universidad Concepción and Simon Casassus (PI) from Universidad de Chile.

One of the great debates in astrophysics refers to the formation pathway of a giant planet like Jupiter.  Giant planets play a dominant role in the architecture of planetary systems as they contain most of the mass and angular momentum.  Two competing theories provide viable formation scenarios for gas giants: the core accretion model and the disk instability model.  Under which conditions is one theory more favorable than the other? And, are these theories mutually exclusive?  The answers to these questions require knowledge of where and when exoplanets form.

The birthplaces of planets are now at the reach of modern observations, most notably with large interferometric arrays, such as the ALMA Observatory, and extreme adaptive optics cameras. These pioneering observations include discoveries of young planets still embedded in their parent protoplanetary disks and are unveiling the physical processes happening in protoplanetary disks that will shape the architecture of future planetary systems, shedding light on the origin of the Solar System. Now we face the necessity to measure the mass of these young exoplanets and understand their growth, which is thought to be regulated by a circumplanetary or ‘proto-lunar’ disk, i.e. the small accretion disk that will form exo-moons.  This requires advances in observations, simulations, and imaging techniques that we are only beginning to develop.