tokens: Acknowledgements We would like to thank Leonardo Testi, Hauyu Baobab Liu, Jonathan Williams, Peter Abraham, Agnes Kospal, Klaus Pontoppidan, Giovanni Rosotti, Thomas Haworth, Colin McNally, Willy Kley, Antonella Natta, Nienke van der Marel, Ewine van Dishoeck, Ralf Klessen, Philipp Girichidis, Patrick Hennebelle, Mario van den Ancker, Monika Petr-Gotzens, Adriana Pohl, Carsten Dominik, for useful discussions, and Daniel Thun for help with the Binac Cluster. The authors acknowledgesupport by the High Performance and Cloud Computing Group at the Zentrum für Datenverarbeitung of the University of Tübingen, the state of Baden-Württemberg through bwHPC and the German Research Foundation (DFG) through grant no INST 37/935-1 FUGG. This research was supported by the Munich Institute for Astro- and Particle Physics (MIAPP) of the DFG cluster of excellence “Origin and Structure of the Universe”, in particular the MIAPP workshop “Protoplanetary Disks and Planet Formation” in June 2017 where many of the above discussions took place which considerably helped to improve the argumentation. Part of this work was also funded by the DFG Forschergruppe FOR 2634 “Planet Formation Witnesses and Probes: Transition Disks” under grant DU 414/23-1. F.G. acknowledges support from DFG Schwerpunktprogramm SPP 1992 “Diversity of Extrasolar Planets” grant DU 414/21-1. The research of M.K. is supported by a research grant of the Independent Research Foundation Denmark (IRFD) (international postdoctoral fellow, project number: 8028-00025B). The hydrodynamics models were done with the PLUTO code ( http://plutocode.ph.unito.it ). Some supporting models (not shown in this paper) were performed with the AREPO code ( https://wwwmpa.mpa-garching.mpg.de/~volker/arepo/ ). Finally, we would like to thank the anonymous referee for his/her patience and useful suggestions to improve the paper.
ner_tags: O O O O O O B-Person I-Person B-Person I-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person I-Person I-Person B-Person I-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person I-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person O O O O B-Person I-Person O O O O B-ComputingFacility I-ComputingFacility O O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility O O B-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization O B-Location I-Location I-Location O B-ComputingFacility O O B-Organization I-Organization I-Organization B-Organization O B-Grant I-Grant I-Grant I-Grant I-Grant O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O O B-Organization B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O B-Organization B-Event I-Event I-Event I-Event I-Event I-Event I-Event I-Event I-Event O O O O O O O O O O O O O O O O O O O O O O O O B-Organization B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O B-Grant I-Grant I-Grant B-Person O O O B-Organization B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O O B-Person O O O O O O O O B-Organization I-Organization I-Organization I-Organization B-Organization B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship O O O O O O O B-Software O O B-URL O O O O O O O O O O O O O B-Software O O B-URL O O O O O O O O O O O O O O O O O O O O