Acknowledgements:

VS, RW, and RP acknowledge support by the European Research Council under ERC-StG EXAGAL-308037, and would
like to thank the Klaus Tschira Foundation. SG is employed at the Flatiron Institute which is
supported by the Simons Foundation. PT and SG were supported by NASA through Hubble Fellowship grants
HST-HF-51384.001-A and HST-HF2-51341.001-A, respectively. MV acknowledges support from a MIT RSC award, the
Alfred P. Sloan Foundation, and by NASA ATP grant NNX17AG29G. JN acknowledges support from NSF AARF award AST-1402480.

All of the primary TNG simulations have been run on the
Cray XC40 Hazel Hen
supercomputer at the High Performance Computing Center Stuttgart (HLRS) in Germany.
They have been made possible by the Gauss Centre for Supercomputing (GCS) large-scale
project proposals GCS-ILLU and GCS-DWAR. GCS is the alliance of the three national
supercomputing centres HLRS (Universitaet Stuttgart), JSC (Forschungszentrum Julich), and
LRZ (Bayerische Akademie der Wissenschaften), funded by the German Federal Ministry of
Education and Research (BMBF) and the German State Ministries for Research of Baden-Wuerttemberg
(MWK), Bayern (StMWFK) and Nordrhein-Westfalen (MIWF).
Further simulations were run on the Hydra and Draco supercomputers at the Max Planck
Computing and Data Facility (MPCDF, formerly known as RZG) in Garching near Munich, in
addition to the Magny system at HITS in Heidelberg. Additional computations were carried out
on the Odyssey2 system supported by the FAS Division
of Science, Research Computing Group at Harvard University, and the Stampede supercomputer at
the Texas Advanced Computing Center through the XSEDE project AST140063.