This research was supported by the Victorian Life Sciences Computation Initiative (VLSCI), grant ref. UOM0005, on its Peak Computing Facility hosted at the University of Melbourne, an initiative of the Victorian Government, Australia. Part of this work was performed on the gSTAR national facility at Swinburne University of Technology. gSTAR is funded by Swinburne and the Australian Governments Education Investment Fund. This research programme is funded by the Australian Research Council through the ARC Laureate Fellowship FL110100072 awarded to JSBW. CP acknowledges support of ARC DP130100117 and DP140100198, and ARC Future Fellowship FT130100041. AM acknowledges support from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (grant agreement no. 638809 AIDA). We thank Volker Springel for making his gadget-2 and subfind codes available to us and Peter Behroozi for making his rockstar code available. We also thank N. Gnedin for several very useful comments on our manuscript.

O O O O O O B-Grant I-Grant I-Grant I-Grant I-Grant B-Grant B-Grant I-Grant I-Grant O O B-ComputingFacility I-ComputingFacility I-ComputingFacility O O O B-Organization I-Organization I-Organization O O O O B-Organization I-Organization B-Location O O O O O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility O B-Organization I-Organization I-Organization I-Organization B-ComputingFacility O O O B-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O O B-Organization I-Organization I-Organization O O B-Organization B-Fellowship I-Fellowship I-Fellowship O O B-Person B-Person O O O B-Organization B-Grant O B-Grant O B-Organization B-Fellowship I-Fellowship I-Fellowship B-Person O O O O B-Organization I-Organization I-Organization B-Organization O O B-Location I-Location B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Grant I-Grant I-Grant I-Grant I-Grant O O B-Person I-Person O O O B-Software O B-Software O O O O O B-Person I-Person O O O B-Software O O O O O B-Person I-Person O O O O O O O O


We thank the McDonald Observatory staff in West Texas for their hospitality during the observing runs for this research. P. W. C. especially thanks David Doss for his help, without which the collection of some of this data would not have been possible. P. W. C. would also like to acknowledge Pat Hartigan for his comments and discussion throughout this project. We thank the referee for their helpful comments which improved the quality of this manuscript. This research has made use of the SIMBAD database and the NASA Astrophysics Data System. We acknowledge partial support for this research from the NSF through grant 1212122, from NASA Astrophysics Data Analysis Program through grant NNX13AF09G, and from Space Telescope Science Institute through grant HST-60-12996.001, all made to Rice University.

O O O B-Observatory I-Observatory O O B-Location I-Location O O O O O O O O O O B-Person I-Person I-Person O O B-Person I-Person O O O O O O O O O O O O O O O O O B-Person I-Person I-Person O O O O O B-Person I-Person O O O O O O 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-Database I-Database O O B-Archive I-Archive I-Archive I-Archive O O O O O O O O O B-Organization O B-Grant I-Grant O B-Organization B-Grant I-Grant I-Grant I-Grant O B-Grant I-Grant O O B-Organization I-Organization I-Organization I-Organization O B-Grant I-Grant O O O B-Organization I-Organization


The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. We like to thank Juan Pablo Perez-Beaupuits for providing the ionized, atomic, and molecular data of M17 presented in Fig. 13 . H.B. acknowledges support from the European Research Council under the Horizon 2020 Framework Program via the ERC Consolidator Grant CSF-648505. R.S.K. and S.C.O.G. acknowledge support from the European Research Council via the ERC Advanced Grant STARLIGHT (project number 339177). R.S.K. and S.C.O.G. furthermore thank for financial help from the DFG via SFB 881 “The Milky Way System” (subprojects B1, B2, and B8) and SPP 1573 “Physics of the Interstellar Medium”.

O B-Observatory I-Observatory I-Observatory I-Observatory O O O O O B-Organization I-Organization I-Organization O O O O O B-Organization I-Organization I-Organization O O O O B-Person I-Person I-Person O O O O O O O O O B-CelestialObject O O O O O B-Person O O O O B-Organization I-Organization I-Organization O O B-Grant I-Grant I-Grant I-Grant O O B-Organization B-Grant I-Grant I-Grant B-Person O B-Person O O O O B-Organization I-Organization I-Organization O O B-Organization B-Grant I-Grant I-Grant B-Grant I-Grant I-Grant B-Person O B-Person O O O O O O O B-Organization O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Grant I-Grant B-Grant O B-Grant O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant


ACKNOWLEDGEMENTS We thank Javier Román and Raúl Infante for providing the extended SDSS r -band PSF, and Sebastién Comerón for a number of useful suggestions. We acknowledge support from the Spanish Ministry of Economy and Competitiveness (MINECO) under grant numbers AYA2013-41243-P, AYA2016-76219-P and AYA2016-77237-C3-1-P. J.H.K. and I.T.C. acknowledge financial support from the European Union’s Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement No. 721463 to the SUNDIAL ITN network and from the Fundación BBVA under its 2017 programme of assistance to scientific research groups, for the project ‘Using machine-learning techniques to drag galaxies from the noise in deep imaging’. J.H.K. thanks the Leverhulme Foundation for the award of a Visiting Professorship at Liverpool John Moores University. Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, University of Cambridge, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University. This work is based on archival data from the Spitzer Space Telescope available in the NASA/ IPAC Infrared Science Archive, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Some of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for non- HST data is provided by the NASA Office of Space Science via grant NNX09AF08G and by other grants and contracts.This research has made use of different Python packages and of NASA’s Astrophysics Data (NED) System Bibliographic Services, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautic and Space Administration. We acknowledge constructive remarks by an anonymous referee.

O O O B-Person I-Person O B-Person I-Person O O O O B-Survey B-Wavelength I-Wavelength B-Model O B-Organization I-Organization O O O O O O O O O O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O O O B-Grant B-Grant O B-Grant B-Person O B-Person O O O O O B-Location I-Location B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O B-Collaboration I-Collaboration I-Collaboration O O O B-Organization I-Organization O O O O O O O O O O O O O B-Proposal I-Proposal I-Proposal I-Proposal I-Proposal I-Proposal I-Proposal I-Proposal I-Proposal I-Proposal I-Proposal I-Proposal B-Person O O B-Organization I-Organization O O O O O B-Fellowship I-Fellowship O B-Organization I-Organization I-Organization I-Organization O O B-Survey O O O O O B-Organization I-Organization I-Organization I-Organization O O O O B-Organization I-Organization I-Organization O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Survey O O O O B-Collaboration I-Collaboration I-Collaboration O O O O O O B-Organization I-Organization O O B-Organization I-Organization I-Organization O B-Collaboration I-Collaboration I-Collaboration B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization O B-Collaboration I-Collaboration I-Collaboration O B-Collaboration I-Collaboration I-Collaboration B-Organization I-Organization O B-Organization I-Organization I-Organization I-Organization I-Organization O B-Collaboration I-Collaboration I-Collaboration I-Collaboration I-Collaboration B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization B-Organization I-Organization O B-Collaboration I-Collaboration I-Collaboration B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization B-Organization I-Organization B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization O B-Organization I-Organization O O O O O O O O O B-Telescope I-Telescope I-Telescope O O O B-Archive I-Archive I-Archive I-Archive I-Archive O O O O O B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O O O O O O O B-Archive I-Archive I-Archive I-Archive I-Archive B-Archive B-Organization O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O B-Organization B-Grant I-Grant O O B-Archive O O B-Telescope O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Grant O O O O O O O O O O O O B-Software O O O B-Archive I-Archive I-Archive I-Archive I-Archive I-Archive I-Archive O O O O O B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O O O


Acknowledgements I thank David M. Hernandez for a critical reading and Scott Tremaine for useful conversations on symplecticity and time symmetry. WD is partly supported by STFC grant ST/N000757/1.

O O O B-Person I-Person I-Person O O O O O B-Person I-Person O O O O O O O O B-Person O O O O B-Organization B-Grant I-Grant


ACKNOWLEDGEMENTS We greatly appreciate valuable comments from Christopher M. Hirata and Patrick Mcdonald. We also thank Tim Eifler for providing the source galaxy redshift information for the PWL-Stage III and IV surveys adopted in this work. ZD, DC, and H-JS are supported by the U.S. Department of Energy, Office of Science,Office of High Energy Physics under Award Number DE-SC0014329. SS was supported in part by JSPS KAKENHI Grant Number JP15H05896 and by World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan. This research used the DESI allocation resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231.

O O O O O O O B-Person I-Person I-Person O B-Person I-Person O O O B-Person I-Person O O O O O O O O O B-Survey I-Survey I-Survey I-Survey I-Survey O O O O B-Person B-Person O B-Person O O O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O B-Grant B-Person O O O O O B-Organization B-Grant I-Grant I-Grant I-Grant O O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Grant I-Grant B-Organization B-Location O O O O B-Instrument O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility B-ComputingFacility O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O B-Grant


O O O O O B-Grant I-Grant O O B-Observatory I-Observatory I-Observatory O O O O O B-Telescope I-Telescope I-Telescope O O O O O B-Organization I-Organization I-Organization O O B-Observatory O O O B-Organization O B-Grant I-Grant O B-CelestialObject I-CelestialObject O B-Grant B-Dataset I-Dataset I-Dataset I-Dataset I-Dataset I-Dataset O O B-Organization I-Organization I-Organization I-Organization O O O O B-Telescope I-Telescope I-Telescope O O B-Organization O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O O B-Organization O O O O O O B-Observatory I-Observatory I-Observatory B-Telescope I-Telescope I-Telescope O O O B-Organization I-Organization I-Organization B-Person I-Person I-Person O O B-Observatory O O O O O O O O O O O O O O O O O O O O O O O B-ComputingFacility O O B-Organization B-Location I-Location O B-Archive I-Archive I-Archive I-Archive I-Archive O B-Organization O B-Location I-Location O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization O B-Location I-Location O O O O O O O O O O B-Organization I-Organization I-Organization B-Organization B-Mission I-Mission O B-URL O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-URL O O O O B-Organization O O O O O O O O O O O O B-Collaboration I-Collaboration I-Collaboration


O O O O O O O O O O O O O O O O O O O O B-Person I-Person O B-Person I-Person O O O O O O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-Grant I-Grant I-Grant O O B-Location B-Organization I-Organization I-Organization B-Organization B-Grant I-Grant I-Grant O O O B-Organization I-Organization I-Organization B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O O O B-Instrument I-Instrument I-Instrument I-Instrument B-Instrument O O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O O O O O O B-Location B-Organization I-Organization I-Organization O B-Grant I-Grant O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O B-Grant I-Grant I-Grant O B-Organization O O O O O O O O O B-Organization I-Organization I-Organization B-Organization B-Mission I-Mission O B-URL O O O O B-Telescope B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-URL O O O O B-Organization O O O O O O O O O O O O O B-Collaboration I-Collaboration I-Collaboration O O O O O O B-Archive I-Archive I-Archive I-Archive I-Archive I-Archive O B-Database I-Database O O B-Database I-Database O O O B-Organization B-Location I-Location O O O O O O O B-Database I-Database O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O B-Database I-Database O O B-Organization I-Organization O B-Organization I-Organization I-Organization I-Organization O B-Location O O B-Organization I-Organization I-Organization O O O O O O B-Observatory I-Observatory I-Observatory O O B-Organization I-Organization I-Organization I-Organization I-Organization


Acknowledgements Optical, Spectroscopic and Infrared Remote Imaging System (OSIRIS) was built by a consortium of the Max-Planck-Institut für Sonnensystemforschung, in Göttingen, Germany, CISAS-University of Padova, Italy, the Laboratoire d’Astrophysique de Marseille, France, the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, the Research and Scientific Support Department of the European Space Agency, Noordwijk, the Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden and the Institut für Datentechnik und Kommunikationsnetze der Technischen Universität Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), Italy (ASI), France (CNES), Spain (MEC), Sweden (SNSB) and the ESA Technical Directorate is gratefully acknowledged. We thank the ESA teams at ESAC, ESOC and ESTEC for their work in support of the Rosetta mission. We made use of the arcgis 10.2 software together with idl and matlab software to perform the presented analysis.

O B-Instrument I-Instrument I-Instrument I-Instrument I-Instrument I-Instrument I-Instrument B-Instrument O O O O O O O B-Organization I-Organization I-Organization O B-Location I-Location B-Organization I-Organization I-Organization B-Location O B-Organization I-Organization I-Organization I-Organization B-Location O O O O O O O B-Location I-Location O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Location I-Location I-Location O B-Organization I-Organization I-Organization I-Organization I-Organization B-Location I-Location O B-Organization I-Organization I-Organization I-Organization B-Location O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Location O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Location O O O O O O O O B-Location B-Organization B-Location B-Organization B-Location B-Organization B-Location B-Organization B-Location B-Organization O O B-Organization I-Organization I-Organization O O O O O O B-Organization O O B-Organization B-Organization O B-Organization O O O O O O O B-Mission I-Mission O O O O O B-Software I-Software O O O B-Software O B-Software O O O O O O


ACKNOWLEDGEMENTS This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. We thank the referee for his/her thorough reading of the manuscript and timely suggestions to improve it.

O O O O O O O O O O B-Survey I-Survey I-Survey I-Survey I-Survey O O O O O O O B-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization O O O O O O O O O O O O O O O O O


ACKNOWLEDGEMENTS We acknowledge stimulating discussions with Frank van den Bosch, Adi Nusser, Shany Danieli, Yuval Birnboim, Elad Zinger, and Nicolas Cornuault. We thank the editor and the anonymous referee for helping to make the paper more rounded. This work was partly supported by the grants ISF 124/12, I-CORE Program of the PBC/ISF 1829/12, BSF 2014-273, PICS 2015-18, and NSF AST-1405962. FJ is partly supported by the PBC Fellowship. AJR was supported by National Science Foundation (NSF) grant AST-1616710, and as a Research Corporation for Science Advancement Cottrell Scholar. ADC acknowledges financial support from a Marie-Skłodowska-Curie Individual Fellowship grant, H2020-MSCA-IF-2016 Grant agreement 748213 DIGESTIVO. The simulations were performed on the High Performance Computing resources at New York University Abu Dhabi; on the THEO cluster of the Max Planck Institute fr Astronomie and on the HYDRA clusters at the Rechenzentrum in Garching.

O O O O O O B-Person I-Person I-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person O B-Person I-Person O O O O O O O O O O O O O O O O O O O O O O O B-Grant I-Grant I-Grant B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Grant I-Grant B-Grant I-Grant O B-Organization B-Grant B-Person O O O O O B-Fellowship I-Fellowship B-Person O O O B-Organization I-Organization I-Organization B-Organization B-Grant I-Grant O O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship B-Person O O O O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship O O O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-ComputingFacility I-ComputingFacility O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O B-ComputingFacility I-ComputingFacility O O B-Organization I-Organization I-Organization


We warmly thank A. K. Vivas for useful discussions and information regarding her team’s variability search around Cen. We also thank the anonymous referee for useful comments that helped improve the presentation of our results. Support for this project is provided by the Ministry for the Economy, Development, and Tourism’s Programa Iniciativa Científica Milenio through grant IC 120009, awarded to the Millennium Institute of Astrophysics (MAS); by Proyecto Basal PFB-06/2007; and by FONDECYT grants #1141141 (C.N., F.G., M.C.), #1130196 (F.G., D.M.), #3130320 (R.C.R.), and #3130552 (J.A.-G.). C.N. and F.G. acknowledge additional support from CONICYT-PCHA/Magíster Nacional (grants 2012-22121934 and 2014-22141509, respectively).

O O O B-Person I-Person I-Person O O O O O O O O O O O B-CelestialObject O 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 I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O O B-Organization I-Organization I-Organization I-Organization B-Organization O B-Grant I-Grant I-Grant O O B-Organization B-Grant I-Grant B-Person B-Person B-Person B-Grant B-Person B-Person B-Grant B-Person O B-Grant B-Person B-Person O B-Person O O O O B-Organization B-Organization B-Grant I-Grant O B-Grant O


The authors thank the anonymous referee for helpful comments on the manuscript. Hinode is a Japanese mission developed and launched by ISAS/JAXA, with NAOJ as domestic partner and NASA and STFC (UK) as international partners. It is operated by these agencies in co-operation with ESA and NSC (Norway). L.-M. Yan thanks H. Peter, Y. Chen, B. Li, L.-P. Yang, and L. Zhang for helpful discussion. The group from Shandong University was supported by grants NSBRSF 2012CB825601 and NNSFC 41274178. The group from Peking University was supported by NNSFC under 41174148, 40890162, and 40931055.

O O O O O O O O O O O O B-Telescope O O O O O O O O B-Organization O B-Observatory O O O O B-Organization O B-Organization B-Location O O O O O O O O O O O O B-Organization O B-Organization B-Location B-Person I-Person O B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person O B-Person I-Person O O O O O O B-Organization I-Organization O O O B-Grant I-Grant I-Grant O B-Grant I-Grant O O O B-Organization I-Organization O O O B-Organization O B-Grant B-Grant O B-Grant


This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 638809 – AIDA). J.C.P. is supported by an NSF Astronomy and Astrophysics Fellowship under award AST-1302774.

O O O O O O O B-Organization I-Organization I-Organization B-Organization O O B-Location I-Location B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Person O O O O B-Organization B-Fellowship I-Fellowship I-Fellowship I-Fellowship O B-Fellowship I-Fellowship


ACKNOWLEDGEMENTS This paper uses observations made at the South African Astronomical Observatory; is based partly upon work supported financially by the University of the Western Cape and the National Research Foundation of South Africa; and has made use of the SIMBAD data base operated at the Centre de Données astronomiques de Strasbourg (CDS) in Strasbourg, France. We are grateful to the referee, Prof. M.D. Reed, for comments which have enabled the authors to improve this paper.

O O O O O O O O B-Observatory I-Observatory I-Observatory I-Observatory O O O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O B-Database I-Database I-Database O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O B-Location I-Location O O O O O O B-Person I-Person I-Person O O O O O O O O O O O


Acknowledgements This research has made use of the high performance computing cluster at the Abdus Salam Centre for Physics, Pakistan and the supercomputer Leftraru, Chile. The first author (R.R.) gratefully acknowledges support from the Department of Astronomy, University of Concepcion, Chile. The first author R.R. and third author D.R.G.S. are thankful for funding through the “Concurso Proyectos Internacionales de Investigación, Convocatoria 2015” (project code PII20150171). D.R.G.S. is further thankful for funding via Fondecyt regular (project code 1161247) and via the Chilean BASAL Centro de Excelencia en Astrofísica yTecnologías Afines (CATA) grant PFB-06/2007, and ALMA-Conicyt project (proyecto code 31160001). The second author (S.V.) developed the computer code that has been used in this work on the HPC system Thinking at KU Leuven, which is part of the infrastructure of the FSC (Flemish Supercomputing Center). We thank the KU leuven support team for helping with the use of this system. The second author also gratefully acknowledges the support of Prof. Dr. Stefaan Poedts and Prof. Dr. Rony Keppens for having provided both access and funding, which made the use of the KU Leuven HPC infrastructure possible.

O O O O O O O O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Location O O B-ComputingFacility I-ComputingFacility B-Location O O O B-Person O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Location O O O B-Person O O O B-Person O O O O O O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Grant I-Grant I-Grant B-Person O O O O O O B-Organization O B-Grant I-Grant I-Grant O O O B-Location B-Organization B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-Grant I-Grant O B-Observatory O B-Grant I-Grant I-Grant O O O B-Person O O O O O O O O O O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility O B-Organization I-Organization O O O O O O O O B-ComputingFacility B-ComputingFacility I-ComputingFacility I-ComputingFacility O O O B-Organization I-Organization I-Organization I-Organization O O O O O O O O O O O O O O O O O B-Person I-Person I-Person I-Person O B-Person I-Person I-Person I-Person O O O O O O O O O O O O O B-Organization I-Organization B-ComputingFacility I-ComputingFacility O


We thank Vicky Kaspi and Sterl Phinney for helpful comments on the manuscript. This work was supported in part by NSF grant AST-1312034.

O O B-Person I-Person O B-Person I-Person O O O O O O O O O O O O O B-Organization B-Grant I-Grant


We thank I. Liodakis and A. Marsher for helpful discussions of jet polarization physics. This work was supported in part by NASA grant NNM17AA26C.

O O B-Person I-Person O B-Person I-Person O O O O O O O O O O O O O O B-Organization B-Grant I-Grant


AZ acknowledges funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement no. 617001. NDK acknowledges partial support by the ‘RoboPol’ project, which is implemented under the ‘ARISTEIA’ Action of the ‘Operational Program Education and Lifelong Learning’ and is co-funded by the European Social Fund (ESF) and National Resources. This research has made use of NASA's Astrophysics Data System. This research has made use of data and/or software provided by the High Energy Astrophysics Science Archive Research Center (HEASARC), which is a service of the Astrophysics Science Division at NASA/GSFC and the High Energy Astrophysics Division of the Smithsonian Astrophysical Observatory.

B-Person O O O O B-Organization I-Organization I-Organization O O B-Location I-Location B-Grant I-Grant I-Grant B-Grant O O O B-Grant B-Person O O O O O B-Grant O O O O O O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O O O O B-Grant I-Grant I-Grant B-Grant O B-Organization I-Organization O O O O O O B-Archive I-Archive I-Archive I-Archive O O O O O O O O O O O O B-Archive I-Archive I-Archive I-Archive I-Archive I-Archive I-Archive B-Archive O O O O O O B-Organization I-Organization I-Organization O B-Organization O O B-Organization I-Organization I-Organization I-Organization O O B-Observatory I-Observatory I-Observatory


The authors acknowledge the referee for his/her useful comments that helped to improve the manuscript. JAFO acknowledges financial support by the Agenzia Spaziale Italiana (ASI) under the research contract 2018-31-HH.0. JAFO and KMD acknowledge financial support by the Hellenic Foundation for Research and Innovation (HFRI), under the first call for the creation of research groups by postdoctoral researchers that was launched by the General Secretariat For Research and Technology (project number 1882). MPS acknowledges support from the Comunidad de Madrid, Spain, through Atracción de Talento Investigador Grant 2018-T1/TIC-11035 and STFC through grants ST/N000919/1 and ST/N002717/1. CR acknowledges support from the CONICYT+PAI, Convocatoria Nacional subvención a instalación en la academia, convocatoria año 2017 PAI77170080. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2017.1.00236.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

O O O O O O O O O O O O O O O B-Person O O O O O B-Organization I-Organization I-Organization B-Organization O O B-Grant I-Grant I-Grant B-Person O B-Person O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O O O O O O O O O O O O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Grant I-Grant I-Grant B-Person O O O O B-Organization I-Organization I-Organization B-Location O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O B-Organization O B-Grant I-Grant O B-Grant B-Person O O O O B-Organization B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Grant I-Grant I-Grant I-Grant O O O O O O O B-Observatory O B-Identifier B-Observatory O O O O B-Observatory O O O O B-Organization B-Location O B-Organization B-Location O O B-Organization B-Location B-Organization O B-Organization B-Location O B-Organization B-Location I-Location I-Location O O O O B-Location I-Location I-Location O B-Observatory I-Observatory I-Observatory O O O B-Observatory B-Organization O B-Observatory O B-Observatory I-Observatory I-Observatory I-Observatory O O O O O B-Organization I-Organization I-Organization O O O O O B-Organization I-Organization I-Organization


I sincerely thank Pavel Naselsky, Sebastian von Hausegger and James Creswell for valuable discussions and suggestions, as well as the anonymous referee for carefully reading the article and giving very helpful comments. This research has made use of data/product from the WMAP (The WMAP data release 2013) and Planck (The Planck data release 2015) collaborations. Some of the results in this paper are derived using the HEALPix ( Górski et al. 2005 ) package. This work was partially funded by the Danish National Research Foundation (DNRF) through establishment of the Discovery Center and the Villum Fonden through the Deep Space project. Hao Liu is also supported by the Youth Innovation Promotion Association, CAS.

O O O B-Person I-Person B-Person I-Person I-Person O B-Person I-Person O O O O O O 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-Telescope O B-Dataset I-Dataset I-Dataset I-Dataset O B-Telescope O B-Dataset I-Dataset I-Dataset I-Dataset O O O O O O O O O O O O B-Software O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O B-Organization I-Organization I-Organization I-Organization B-Organization O O O O B-Organization I-Organization O O B-Organization I-Organization O O B-Grant I-Grant I-Grant B-Person I-Person O O O O O B-Organization I-Organization I-Organization I-Organization B-Organization


The material is based upon work supported by the National Aeronautics and Space Administration under Prime Contract Number NAS2-03144 awarded to the University of California, Santa Cruz, University Affiliated Research Center. This work was supported in part by the National Aeronautics and Space Administration's Ames Research Center under a center investment fund. It was carried out at the NASA Ames Research Center. Any opinions, findings, and conclusions or recommendations expressed in this article are those of the authors and do not necessarily reflect the views of the National Aeronautics and Space Administration.

O O O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O B-Grant I-Grant I-Grant I-Grant O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O O O O O O B-Organization I-Organization I-Organization I-Organization O 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 I-Organization I-Organization I-Organization I-Organization


The authors thank the anonymous referee for insightful comments that greatly improved this paper. We also thank Peter Gao and Diana Powell for providing paper manuscripts, and Shigeru Ida, Hidekazu Tanaka, Xi Zhang, Chris Ormel, Ryo Tazaki, Yamira Miguel, Masahiro Ogihara, Yuichi Ito, and Yui Kawashima for helpful comments. This work was supported by JSPS Grants-in-Aid for Scientific Research (#15H02065, 16H04081, 16K17661, 18J14557) and the Foundation for Promotion of Astronomy.

O O O O O O O O O O O O O O O O O B-Person I-Person O B-Person I-Person O O O O O 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 O B-Person I-Person O O O O O O O O B-Organization B-Grant I-Grant I-Grant I-Grant B-Grant B-Grant B-Grant B-Grant O O B-Organization I-Organization I-Organization I-Organization I-Organization


SDO is a mission of NASA's Living With a Star Program. This work used the DAVE4VM code, written and developed by P.W. Schuck at the Naval Research Laboratory. 3D rendering is due to VAPOR ( www.vapor.ucar.edu ) software. The authors sincerely thank Dr. T. Wiegelmann for providing NLFFF code. We acknowledge an extensive usage of the multi-node, multi-processor high performance computing facility at IIA. PV is supported by an INSPIRE grant of AORC scheme under the Department of Science and Technology. XC is supported by NSFC under grants 11303016. We thank the referee for constructive comments and suggestions that greatly helped to improve the manuscript.

B-Observatory O O O O B-Organization B-Grant I-Grant I-Grant I-Grant I-Grant O O O O B-Software I-Software O O O O B-Person I-Person O O B-Organization I-Organization I-Organization O O O O O B-Software O B-URL O O O O O O B-Person I-Person I-Person O O B-Software I-Software O O O O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility B-Person O O O O B-Organization I-Organization O B-Organization I-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Person O O O B-Organization O B-Grant I-Grant O O O O O O O O O O O O O O O O


O O O O O B-Collaboration I-Collaboration I-Collaboration O B-Collaboration I-Collaboration B-Person O O O B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person O B-Person I-Person O O O O B-Person I-Person O O O O O O O O B-Software O O O B-URL O O B-Software B-Citation I-Citation O O O O O O O O O O B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O B-Grant I-Grant I-Grant


The JCMT is operated by the Joint Astronomy Centre on behalf of the Science and Technology Facilities Council of the UK, the National Research Council of Canada and (until 2013 March 31) the Netherlands Organisation for Scientific Research. Additional funds for the construction of SCUBA-2 were provided by the Canada Foundation for Innovation. DJ is supported by the National Research Council of Canada and by a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.

O B-Telescope O O O O B-Organization I-Organization I-Organization O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Location O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O B-Instrument O O O O B-Organization I-Organization I-Organization I-Organization B-Person O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O B-Location B-Organization B-Grant I-Grant O O O O O O O O O B-Survey I-Survey I-Survey I-Survey I-Survey O O O O O O O B-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization


The research of V.F. and J.H. was supported by NASA grants NNX12AH44G, NNX13AF99G, NNX14AF43G, NNX14AJ53G, and NNX14AP24G, and by NSF grant AGS-0955700. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center. The work of J.N. was supported by Narodowe Centrum Nauki through research project DEC-2013/10/E/ST9/00662. The authors thank P.A. Isenberg, K.-I. Nishikawa, G.P. Zank, and E.J. Summerlin for helpful discussions.

O O O B-Person O B-Person O O O B-Organization B-Grant I-Grant B-Grant B-Grant B-Grant O B-Grant O O B-Organization B-Grant I-Grant O O O O O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility B-ComputingFacility B-ComputingFacility O O B-ComputingFacility I-ComputingFacility I-ComputingFacility B-ComputingFacility B-ComputingFacility O B-Organization I-Organization I-Organization O O O B-Person O O O B-Organization I-Organization I-Organization O B-Grant I-Grant I-Grant O O O B-Person I-Person B-Person I-Person B-Person I-Person O B-Person I-Person O O O


H.B.L. is grateful for support from ASIAA. We are extremely grateful to our referee Charles Hull,for the very useful comments. H.B.L. thanks Dr. Steve Myers for the information about polarization calibration sources, and thanks Drs. Akimasa Kataoka, Francisca Kemper, Hiroyuki Hirashita, and Michihiro Takami for useful suggestions. N.H. is supported by the MoST grant 104-2119-M-001-016. J.M.G. acknowledges support from the MICINN (Spain) AYA2014-57369-C3-1-P grant and the MECD (Spain) PRX15/00435 travel grant. C.C.-G. acknowledges support by UNAM-DGAPA-PAPIIT, grant number IA101214. Y.H. is currently supported by JPL/Caltech. Facilities: EVLA , SMA .

B-Person O O O O O B-Organization O O O O O O O B-Person I-Person O O O O B-Person O B-Person I-Person I-Person O O O O O O O O O B-Person I-Person I-Person B-Person I-Person B-Person I-Person O B-Person I-Person O O O B-Person O O O O B-Organization B-Grant I-Grant B-Person O O O O B-Organization B-Location B-Grant O O O B-Organization B-Location B-Grant I-Grant I-Grant B-Person O O O B-Organization B-Grant I-Grant I-Grant B-Person O O O O B-Organization O B-Telescope O B-Telescope O


Acknowledgements We thank Andrew Fletcher and Aritra Basu for fruitful discussions, and Aritra Basu also for helpful comments on the manuscript. We acknowledge a helpful suggestion of the anonymous referee. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. RAMW acknowledges support from the National Science Foundation through grant AST-1615594.

O O O B-Person I-Person O B-Person I-Person O O O O B-Person I-Person O O O O O O O O O O O O O O O O O O O O O O O B-Database I-Database I-Database B-Database O O O O O B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization O O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Person O O O O B-Organization I-Organization I-Organization O B-Grant I-Grant


ACKNOWLEDGEMENTS The authors are very grateful to Bruce Draine and Joseph Weingartner for their valuable and rapid answers to questions regarding their work on the silicate–graphite–PAH dust model. We also thank Simone Bianchi and Andrea Ferrara for their insightful comments on the manuscript. Finally, we would like express our gratitude to the anonymous referee for reading the manuscript with great care and for providing challenging comments that resulted in a constructive discussion and substantial improvements.

O O O O O O O B-Person I-Person O B-Person I-Person O O O O O O O O O O O O O O O O O O O B-Person I-Person O B-Person I-Person O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


This work was supported by a Postdoctoral Fellowship from Mahidol University, Basic Research Grant BRG5880009 from the Thailand Research Fund, the US National Science Foundation Solar Terrestrial program grant AGS-1063439, and NASA grants NNX14AI63G (Heliospheric Grand Challenge Research) and NNX15AB88G (Living with a Star Program). A.P.S. would like to thank Korn Pattanaseri for assistance with computer simulations.

O O O O O O B-Fellowship I-Fellowship O B-Organization I-Organization B-Grant I-Grant I-Grant I-Grant O O B-Organization I-Organization I-Organization O B-Location B-Organization I-Organization I-Organization B-Grant I-Grant I-Grant I-Grant I-Grant O B-Organization O B-Grant B-Grant I-Grant I-Grant I-Grant O B-Grant B-Grant I-Grant I-Grant I-Grant I-Grant B-Person O O O O B-Person I-Person O O O O O


O O O B-Person I-Person B-Location B-Person I-Person B-Location B-Person I-Person B-Location O O O O O O O O O O O O O B-Person I-Person B-Location O O O O O O O O O O O O O O O O B-Software O O O O O O B-Archive I-Archive O B-Organization O B-Citation I-Citation I-Citation I-Citation O O O O O O O B-Organization O B-Organization B-Person O O B-Person I-Person O B-Person I-Person B-Organization O O O O B-Archive I-Archive O O O O O O O O O O O O O O O B-Software O B-Software O B-Software O B-Citation I-Citation O O O O O B-Software O B-Software O B-Software O B-Citation I-Citation O B-Software O B-Citation I-Citation I-Citation O B-Software O B-Citation I-Citation I-Citation I-Citation O B-Software O O B-Software O B-Citation I-Citation O O O O O O O O O O O B-Software O O B-Citation I-Citation O O O O O O B-Software O B-Citation I-Citation O O O O O O O O B-CelestialObject O O O O O O O O B-Software I-Software I-Software I-Software O B-URL O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation O O O O B-Location B-Organization O O B-Grant O O O O O O O O O B-Organization I-Organization I-Organization B-Organization O B-Telescope O B-URL O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-URL O O O O B-Organization O O O O O O O O O O O O O B-Collaboration I-Collaboration I-Collaboration O O O O O O O B-Location I-Location B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O O O O O O B-Organization B-Location B-Organization I-Organization I-Organization O O B-Grant B-Organization B-Organization O B-Grant O B-Organization B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization


We thank the Gemini Observatory staff for their help with our observing program and the anonymous referee for comments that improved the manuscript. J.W., L.J., L.C.H. and X.W. acknowledge support from the National Key RD Program of China (2016YFA0400702, 2016YFA0400703) and from the National Science Foundation of China (grant No. 11473002, 11533001, 11721303). Y.S. acknowledges support from an Alfred P. Sloan Research Fellowship and National Science Foundation grant No. AST-1715579. D.R. acknowledges support from the National Science Foundation under grant No. AST-1614213. M.V. gratefully acknowledges support from the Independent Research Fund Denmark via grant Nos. DFF 4002-00275 and 8021-00130.

O O O B-Observatory I-Observatory O O O O O O O O O O O O O O O O O O B-Person B-Person B-Person O B-Person O O O O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Grant B-Grant O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Grant I-Grant I-Grant B-Grant B-Grant B-Person O O O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship O B-Organization I-Organization I-Organization B-Grant I-Grant I-Grant B-Person O O O O B-Organization I-Organization I-Organization O B-Grant I-Grant I-Grant B-Person O O O O O B-Grant I-Grant I-Grant I-Grant O B-Grant I-Grant I-Grant I-Grant O B-Grant


ACKNOWLEDGEMENTS JB acknowledges support from FONDECYT Postdoctorados grant 3160439 and the DFG cluster of excellence ‘Origin and Structure of the Universe’. This research used the facilities of the Canadian Astronomy Data Centre operated by the National Research Council of Canada with the support of the Canadian Space Agency.

O B-Person O O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship 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 O O O O B-Organization I-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O O B-Organization I-Organization I-Organization


We are grateful to the referee for the constructive input which helped improve the paper. M.A. is grateful to Kim Tolbert and Richard Schwartz for useful discussions on uncertainty computation and general use of RHESSI data analysis tools. Thanks to Brian Dennis for his comments on making the best possible images with RHESSI and for numerous science discussions, and to Joel Allred for helpful discussions on the relative importance of energy loss mechanisms in solar plasmas. This work was supported by a NASA Heliophysics Guest Investigator grant and the RHESSI project.

O O O O O O O O O O O O O O O B-Person O O O B-Person I-Person O B-Person I-Person O O O O O O O O O O B-Telescope O O O O O B-Person I-Person O O O O O O O O O O B-Telescope O O O O O O O B-Person I-Person 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 O O B-Mission I-Mission


The authors would like to thank the data provided by the SDO , SOHO /LASCO, and Wind science teams; the anonymous referee’s valuable comments and suggestions that largely improved the quality of the paper; and the helpful discussions with Dr. Yu Liu and Junchao Hong from Yunnan Observatories, CAS, China. This work is supported by the Natural Science Foundation of China (11773068, 1163308, and 11363007), the Yunnan Science Foundation (2017FB006), and the West Light Foundation of Chinese Academy of Sciences. H.C.C. acknowledges the support by NSFC 11703084, 11633008, and 11873088.

O O O O O O O O O O O B-Observatory O B-Observatory B-Telescope O B-Mission O O O O O O O O O O O O O O O O O O O O O O B-Person I-Person I-Person O B-Person I-Person O B-Observatory I-Observatory B-Organization B-Location O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Grant B-Grant O B-Grant O B-Organization I-Organization I-Organization B-Grant O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Person O O O O B-Organization B-Grant B-Grant O B-Grant


We are grateful to Antonia Rowlinson, Yuri Levin, Eric Thrane, Andrew Melatos, Eric Howell, and Pantelis Pnigouras for enlightening conversations and comments on the manuscript. We are also grateful to the anonymous referee for useful feedback that has improved the manuscript. PDL is supported by an Australian Research Council Discovery Project DP1410102578. KG is supported by the Ramón y Cajal Programme of the Spanish Ministerio de Ciencia e Innovación, by a Humboldt Foundation research visit grant at the University of Tübingen, and also acknowledges travel support from NewCompstar (a COST-funded Research Networking Programme).

O O O O B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person O B-Person I-Person 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-Person O O O O B-Organization I-Organization I-Organization B-Grant I-Grant I-Grant B-Person O O O O B-Grant I-Grant I-Grant I-Grant O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization O O O O O B-Organization I-Organization I-Organization O O O O O O B-Grant O B-Grant I-Grant I-Grant I-Grant


Special thanks goes to Pavol Bobik, Giuliano Boella, Karel Kudela, Marian Putis, and Mario Zannoni for their continuous support of the H el M od project and many useful suggestions. This work is supported by ASI (Agenzia Spaziale Italiana) through a contract ASI-INFN I/002/13/0 and by ESA (European Space Agency) through a contract 4000116146/16/NL/HK. Igor Moskalenko and Troy Porter acknowledge support from NASA grant No. NNX17AB48G. We thank the ACE CRIS instrument team and the ACE Science Center for providing the ACE data.

O O O O B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person O B-Person I-Person O O O O O O B-Survey I-Survey I-Survey I-Survey I-Survey O O O O O O O O O B-Organization B-Organization I-Organization I-Organization O O O B-Grant I-Grant O O B-Organization B-Organization I-Organization I-Organization O O O B-Grant B-Person I-Person O B-Person I-Person O O O B-Organization B-Grant I-Grant I-Grant O O O B-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization O O O B-Telescope O


This work is supported by the National Basic Research Program (“973” Program) of China under Grant No. 2014CB845800 and the National Natural Science Foundation of China (grant Nos. 11573014 and 11473008).

O O O O O O B-Grant I-Grant I-Grant I-Grant B-Grant I-Grant O B-Location O B-Grant I-Grant I-Grant O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Grant I-Grant I-Grant O B-Grant


AGILE is an ASI space mission developed with programmatic support by INAF and INFN. We acknowledge partial support through the ASI grant no. I/028/12/2. This research made use of Enrico, a community-developed Python package to simplify Fermi-LAT analysis (Sanchez Deil 2013 )

B-Mission O O B-Organization O O O O O O O B-Organization O B-Organization O O O O O O B-Organization O B-Grant I-Grant O O O O O B-Software O O B-Software O O O B-Observatory O B-Citation I-Citation I-Citation O


We would like to thank the anonymous referee for important comments and suggestions that have enormously improved the manuscript. This research has made use of data obtained with the Global Millimeter VLBI Array (GMVA), which consists of telescopes operated by the MPIfR, IRAM, Onsala, Metsahovi, Yebes, and the VLBA. The data were correlated with the correlator at the MPIfR in Bonn, Germany. The VLBA is an instrument of the National Radio Astronomy Observatory, a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

O O O O O 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-Telescope I-Telescope I-Telescope I-Telescope B-Telescope O O O O O O O B-Organization B-Telescope B-Telescope B-Telescope B-Telescope O O B-Telescope O O O O O O O O O B-Organization O B-Location I-Location O B-Telescope O O O O O B-Observatory I-Observatory I-Observatory I-Observatory O O O O B-Organization I-Organization I-Organization O O O O O B-Organization I-Organization I-Organization


Acknowledgements We would like to thank F. La Barbera for a referee report that greatly improved this work, as well as for making available the Na-MILES models used in this paper. SPV would like to thank P. Alton for fruitful discussions on the effect of Na on stellar atmospheres and A. Ferré-Mateu for making her optical measurements of NGC 1277 available. This paper made use of the astropy python package (Astropy Collaboration et al. 2013 ), as well as the matplotlib (Hunter 2007 ) and seaborn plotting software (Waskom et al. 2017 ) and the scientific libraries numpy (Van Der Walt, Colbert Varoquaux 2011 ) and scipy (Jones et al. 2001 ). The Oxford SWIFT integral field spectrograph was supported by a Marie Curie Excellence Grant from the European Commission (MEXT-CT-2003-002792, Team Leader: N. Thatte). It was also supported by additional funds from the University of Oxford Physics Department and the John Fell OUP Research Fund. Additional funds to host and support SWIFT at the 200-inch Hale Telescope on Palomar were provided by Caltech Optical Observatories. This work was supported by the Astrophysics at Oxford grants (ST/H002456/1 and ST/K00106X/1) as well as visitors grant (ST/H504862/1) from the UK Science and Technology Facilities Council. SPV is supported by a doctoral studentship supported by STFC grant ST/N504233/1. RCWH was supported by the Science and Technology Facilities Council (STFC grant numbers ST/H002456/1, ST/K00106X/1 ST/J002216/1). RLD acknowledges travel and computer grants from Christ Church, Oxford, and support from the Oxford Hintze Centre for Astrophysical Surveys, which is funded through generous support from the Hintze Family Charitable Foundation.

O O O O O O B-Person I-Person I-Person O O O O O O O O O O O O O O O O B-Model I-Model O O O O B-Person O O O O B-Person I-Person O O O O O O O O O O O O B-Person I-Person O O O O O O B-CelestialObject I-CelestialObject O O O O O O O B-Software B-Software O B-Citation I-Citation I-Citation I-Citation I-Citation O O O O O B-Software B-Citation I-Citation O O B-Software O O B-Citation I-Citation I-Citation I-Citation O O O O O B-Software B-Citation I-Citation I-Citation I-Citation I-Citation I-Citation O O B-Software B-Citation I-Citation I-Citation I-Citation O O B-Instrument I-Instrument I-Instrument I-Instrument I-Instrument O O O O B-Grant I-Grant I-Grant I-Grant O O B-Organization I-Organization B-Grant O O B-Person I-Person O O O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O B-Instrument O O B-Telescope I-Telescope I-Telescope O B-Observatory O O O B-Observatory I-Observatory I-Observatory O O O O O O B-Grant I-Grant I-Grant I-Grant B-Grant O B-Grant O O O B-Grant I-Grant B-Grant O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization B-Person O O O O B-Fellowship I-Fellowship O O B-Organization B-Fellowship I-Fellowship B-Person O O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-Grant I-Grant I-Grant B-Grant B-Grant B-Person O O O O O O B-Organization I-Organization I-Organization O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O O O B-Organization I-Organization I-Organization I-Organization


Acknowledgments We would like to thank the anonymous referee for a prompt and useful report. This publication was made possible by NPRP grant number X-019-1-006 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the author.

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 O O B-Organization I-Organization I-Organization I-Organization O O O B-Organization I-Organization O O O O O O O O O O O


ACKNOWLEDGEMENTS The authors are grateful to the Science and Engineering Research Board (SERB), Govt. of India for monetary support in the form of Ramanujan Fellowship (SB/S2/RJN-061/2015) and Early Career Research Award (ECR/2016/000161). RM and MI would also like to thank IISER Bhopal for providing all the research and infrastructure facilities.

O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-Organization I-Organization I-Organization O O O O O O O B-Fellowship I-Fellowship B-Fellowship O B-Fellowship I-Fellowship I-Fellowship I-Fellowship B-Fellowship B-Person O B-Person O O O O O B-Organization I-Organization O O O O O O O O


ACKNOWLEDGEMENTS We wish to thank David Campbell and Adrian Jenkins for generating the initial conditions and selecting the sample of the Auriga galaxies. IG acknowledges financial support from CONICYT Programa de Astronomía, Fondo ALMA-CONICYT 2017 31170048. AM acknowledges support from CONICYT FONDECYT Regular grant 1181797. FAG acknowledges support from CONICYT FONDECYT Regular grant 1181264. IG, AM, and FAG acknowledge funding from the Max Planck Society through a ‘Partner Group’ grant. FM acknowledges support through the program ‘Rita Levi Montalcini’ of the italian MIUR. This work used the DiRAC Data Centric system at Durham University, operated by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility ( www.dirac.ac.uk ). This equipment was funded by BIS National E-infrastructure capital grant ST/K00042X/1, STFC capital grant ST/H008519/1, and STFC DiRAC Operations grant ST/K003267/1 and Durham University. DiRAC is part of the National E-Infrastructure.

O O O O O B-Person I-Person O B-Person I-Person O O O O O O O O O O O B-CelestialRegion O B-Person O O O O B-Organization B-Grant I-Grant I-Grant B-Organization B-Observatory B-Grant I-Grant B-Person O O O B-Organization B-Organization B-Grant I-Grant I-Grant B-Person O O O B-Organization B-Organization B-Grant I-Grant I-Grant B-Person B-Person O B-Person O O O O B-Organization I-Organization I-Organization O O B-Grant I-Grant I-Grant B-Person O O O O B-Grant I-Grant I-Grant I-Grant O O B-Location B-Organization O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility O B-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization O O O O B-Organization B-ComputingFacility I-ComputingFacility I-ComputingFacility O B-URL O O O O O O B-Organization B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-Grant I-Grant I-Grant O B-Organization B-Grant I-Grant I-Grant I-Grant O B-Organization I-Organization B-ComputingFacility O O O O B-ComputingFacility I-ComputingFacility


We wish to thank an anonymous referee for his/her helpful suggestions. I.P. acknowledges support by Chandra fund 16617814 contract GO2-13021X. The scientific results reported in this article are based on observations made by the Chandra and XMM-Newton X-ray Observatories. This paper also makes use of data obtained as part of the INT Photometric H Survey of the Northern Galactic Plane (IPHAS, www.iphas.org ) carried out at the Isaac Newton Telescope (INT). The INT is operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. All IPHAS data are processed by the Cambridge Astronomical Survey Unit, at the Institute of Astronomy in Cambridge. The bandmerged DR2 catalog was assembled at the Centre for Astrophysics Research, University of Hertfordshire, supported by STFC grant ST/J001333/1. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research makes use of the SIMBAD database, operated at CDS, Strasbourg, France. We also make heavy use of R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ( http://www.R-project.org/ ).

O O O O O O O O O O O B-Person O O O B-Grant I-Grant I-Grant I-Grant I-Grant O O O O O O O O O O O O O O B-Telescope O B-Telescope I-Telescope I-Telescope O O O O O O O O O O O O B-Survey I-Survey I-Survey I-Survey I-Survey I-Survey I-Survey I-Survey I-Survey B-Survey B-URL O O O O O B-Telescope I-Telescope I-Telescope B-Telescope O B-Telescope O O O O B-Location I-Location I-Location I-Location O O B-Organization I-Organization I-Organization O O B-Location B-Observatory I-Observatory I-Observatory I-Observatory I-Observatory I-Observatory O O B-Organization I-Organization I-Organization I-Organization I-Organization O B-Survey O O O O O B-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization O B-Dataset I-Dataset I-Dataset O O O O B-Organization I-Organization I-Organization I-Organization B-Organization I-Organization I-Organization O O B-Organization B-Grant I-Grant O O O O O O O O O B-Telescope I-Telescope I-Telescope I-Telescope O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O B-Database I-Database O O B-Organization B-Location I-Location O O O O O O B-Software O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Location I-Location O B-URL O


Acknowledgements This research is supported by the Agence Nationale de la Recherche (project BxB: ANR-17-CE31-0022). F.L. and F.B. acknowledge support from the European Research Council under the European Union’s Horizon 2020 Research Innovation Framework Programme (ERC grant agreement ERC-2016-ADG-742719). S.M. and S.Z. acknowledge support by the ERC InvariantClass 320959. This work was also supported by the Programme National “Physique et Chimie du Milieu Interstellaire” (PCMI) of CNRS/INSU with INC/INP co-funded by CEA and CNES. We gratefully acknowledge fruitful discussions with J.-F. Cardoso, K. Benabed, P. Lesaffre, B. Godard, A. Gusdorf, E. Falgarone, S. Prunet, and J. Neveu. We finally thank the anonymous referee, whose comments helped to significantly improve the manuscript.

O O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Grant I-Grant I-Grant B-Person O B-Person O O O O B-Organization I-Organization I-Organization O O B-Location I-Location B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Organization B-Grant I-Grant I-Grant B-Person O B-Person O O O O B-Organization B-Grant I-Grant O O O O O O O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Grant O B-Organization O B-Organization O O B-Organization O B-Organization O O O O O O 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 O B-Person I-Person O O O O O O O O O O O O O O


Acknowledgements We are grateful to the anonymous referee for useful comments. HH thanks the staff at LAM for their hospitality and financial and technical support during my stay. HH is supported by the Ministry of Science and Technology grant MOST 105-2112-M-001-027-MY3.

O O O O O O O O O O O B-Person O O O O B-Organization O O O O O O O O O O O B-Person O O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Grant I-Grant I-Grant


This research was supported in part by the National French Program “Physique et Chimie du Milieu Interstellaire” (PCMI) and the French National Research Agency (ANR-13-BS05-0008-02 “IMOLABS”). The Laboratoire d’Excellence “Chemical and Physical Properties of the Atmosphere” (CaPPA) is also acknowledged. The CaPPA project is funded by the French National Research Agency under contract ANR-11-LABX-0005-01, by the Regional Council “Hauts de France” and by the European Regional Development Fund (ERDF). J. Cernicharo thanks the European Research Council and the Spanish Ministry of Science and Innovation through the NANOCOSMOS (SyG-610256) and ASTROMOL (CSD2009-00038) projects, respectively, and the Spanish Ministry of Economy and Competitiveness through the projects AYA2009-07304, and AYA2012-32032. The referee is also thanked for the valuable comments concerning the hyperfine structure.

O O O O O O O O O B-Location O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant B-Grant O O B-Organization I-Organization I-Organization I-Organization B-Grant I-Grant O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O O O O B-Organization O O O O O B-Organization I-Organization I-Organization I-Organization O B-Grant I-Grant O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization B-Organization B-Person I-Person O O B-Organization I-Organization I-Organization O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Grant B-Grant O B-Grant B-Grant O O O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Grant I-Grant O B-Grant O O O O O O O O O O O O O


JC thanks Graca Rocha and especially Silvia Galli for discussions about the effect of variations of fundamental constants, which helped clarifying the comparison with the previous literature. JC is supported by the Royal Society as a Royal Society University Research Fellow at the University of Cambridge, UK. YAH is supported by NSF Grant No. 0244990, NASA NNX15AB18G, the John Templeton Foundation, and the Simons Foundation. Use of the GPC supercomputer at the SciNet HPC Consortium is acknowledged. SciNet is funded by: the Canada Foundation for Innovation under the auspices of Compute Canada; the Government of Ontario; Ontario Research Fund - Research Excellence; and the University of Toronto.

B-Person O B-Person I-Person O O B-Person I-Person O O O O O O O O O O O O O O O O O O O B-Person O O O O B-Organization I-Organization O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship O O B-Organization I-Organization I-Organization B-Person B-Person O O O B-Organization B-Grant I-Grant I-Grant B-Organization B-Grant O B-Organization I-Organization I-Organization O O B-Organization I-Organization O O O B-ComputingFacility I-ComputingFacility O O B-ComputingFacility I-ComputingFacility I-ComputingFacility O O B-ComputingFacility O O O O B-Organization I-Organization I-Organization I-Organization O O O O B-Organization I-Organization O B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization


Acknowledgments We thank the anonymous referee for their comments and suggestions, which have greatly improved the paper. We also thank Kevin Luhman for making his data available to us prior to publication, and for comments and suggestions on the original manuscript. We thank the authors of Parker etal. ( 2014 ) for providing the material for Section 3.1 . RJP acknowledges support from the Royal Society in the form of a Dorothy Hodgkin Fellowship.

O O O O O O O O O O O O O O O O O O O O B-Person I-Person 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-Citation I-Citation I-Citation I-Citation I-Citation O O O O O O O O B-Person O O O O B-Organization I-Organization O O O O O B-Fellowship I-Fellowship I-Fellowship


O O O O O O O O O O B-Survey O O O B-Observatory B-Observatory I-Observatory I-Observatory I-Observatory O B-Survey O O O O O O O O O O O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O O B-Grant B-Person O O O O B-Organization O B-Fellowship O O O O B-Organization I-Organization I-Organization O B-Person O B-Person O O O O B-Organization O O O B-Grant B-Person O O O B-Organization O O B-Organization I-Organization I-Organization O O O O O O O B-Organization I-Organization I-Organization B-Organization O O B-Location I-Location B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O O B-Grant O O O O B-Organization I-Organization I-Organization O B-Person B-Person B-Person B-Person O B-Person O O O O B-Organization O O B-Grant B-Person O O O B-Organization O B-Grant O O O O B-Organization B-Grant B-Organization B-Person O O O O B-Location B-Organization O O B-Grant O O O O B-Fellowship I-Fellowship I-Fellowship O O O B-Organization I-Organization I-Organization O B-Person B-Person B-Person O B-Person O O O O O O O O B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O O O B-Organization I-Organization I-Organization I-Organization B-Organization B-Person O O O O B-Organization O B-Grant O O O O O O O O O B-Organization I-Organization I-Organization B-Organization O B-Telescope O B-URL O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-URL O O O O B-Organization O O O O O O O O O O O O O B-Collaboration I-Collaboration I-Collaboration O O O O O O O B-Archive I-Archive I-Archive O O O O O B-Organization I-Organization I-Organization I-Organization O O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Grant I-Grant I-Grant


ACKNOWLEDGEMENTS FDP is supported by the Science and Technology Facilities Council. MJB acknowledges European Research Council funding by grant ERC-2015-AdG 694520 SNDUST.

O B-Person O O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Person O B-Organization I-Organization I-Organization O O B-Grant I-Grant I-Grant I-Grant


The authors would like to thank S. Sulis for useful discussions regarding colored noise and periodograms, and J. Löhner-Böttcher for sharing results from the LARS spectrograph. The authors also thank the anonymous referee for useful comments, which improved the clarity of this manuscript. H.M.C. acknowledges the financial support of the National Centre for Competence in Research PlanetS supported by the Swiss National Science Foundation (SNSF); S.S., H.M.C, and C.A.W acknowledge support from the Leverhulme Trust. W.J.C., G.R.D., and C.A.W. acknowledge support from the UK Science and Technology Facilities Council (STFC), including grants ST/I001123/1 and ST/P000312/1. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant agreement no.: DNRF106). S.H.S. was supported by NASA Heliophysics LWS grant NNX16AB79G, and M.L.P. was supported by the NSF-REU solar physics program at SAO, grant number AGS-1560313. Some of this work was performed under contract with the California Institute of Technology (Caltech)/Jet Propulsion Laboratory (JPL) funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute (R.D.H.). This work used the DiRAC Data Centric system at Durham University, operated by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility; DiRAC is part of the National E-Infrastructure. This research has made use of NASA’s Astrophysics Data System Bibliographic Services, as well as the VALD database operated at Uppsala University, the Institute of Astronomy RAS in Moscow, and the University of Vienna. Software: MURaM (Vögler et al. 2005 ; Shelyag Przybylski 2014 ; Shelyag 2015 ); OPAL (Rogers et al. 1996 ; Rogers Nayfonov 2002 ); NICOLE (Socas-Navarro 2015 ; Socas-Navarro et al. 2015 ).

O O O O O O B-Person I-Person O O O O O O O O O B-Person I-Person O O O O O B-Instrument I-Instrument O O O O O O O O O O O O O O O O O B-Person O O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization B-Organization B-Person B-Person O B-Person O O O O B-Organization I-Organization B-Person B-Person O B-Person O O O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O B-Grant I-Grant O B-Grant O O O B-Organization I-Organization I-Organization O O O O B-Organization I-Organization I-Organization I-Organization B-Grant I-Grant I-Grant I-Grant B-Person O O O B-Organization B-Grant I-Grant I-Grant I-Grant O B-Person O O O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship O B-Observatory B-Fellowship I-Fellowship I-Fellowship O O O O O O O O O O B-Organization I-Organization I-Organization I-Organization B-Organization B-Organization I-Organization B-Organization O O B-Organization O O B-Fellowship I-Fellowship I-Fellowship O O O B-Organization I-Organization I-Organization I-Organization B-Person O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility O B-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization O O O O B-Organization B-ComputingFacility I-ComputingFacility I-ComputingFacility B-ComputingFacility O O O O B-ComputingFacility I-ComputingFacility O O O O O O B-Archive I-Archive I-Archive I-Archive I-Archive I-Archive O O O O B-Database I-Database O O B-Organization I-Organization O B-Organization I-Organization I-Organization I-Organization O B-Location O O B-Organization I-Organization I-Organization O B-Software B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation O B-Citation I-Citation O B-Software B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation O B-Software B-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O


We thank the anonymous referee for insightful comments on this manuscript and Jo Bovy for useful discussions. This work has been supported by a postdoctoral grant from the Centre National d'Etudes Spatiales (CNES) for GM. RG acknowledges support through the DFG Research Centre SFB-881 ‘The Milky Way System’ through project A1 .

O O O O O O O O O O O O B-Person I-Person O O O O O O O O O O O O O O B-Organization I-Organization I-Organization I-Organization B-Organization O B-Person B-Person O O O O B-Organization I-Organization I-Organization B-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant I-Grant O


The authors thank an anonymous referee whose comments helped to improve the scientific content of this work. FP acknowledges support from a post-doctoral STFC fellowship and thanks Inga Cebotaru for carefully reading the manuscript and improve the style. RR acknowledges funding by the graduate college Astrophysics of cosmological probes of gravity by Landesgraduiertenakademie Baden-Wrttemberg.

O O O O O O O O O O O O O O O O O B-Person O O O O B-Fellowship I-Fellowship I-Fellowship O O B-Person I-Person O O O O O O O O O B-Person O O O O B-Organization I-Organization I-Organization O O O O O O B-Organization I-Organization


Acknowledgements We are very grateful to the staff of the Observatorio del Teide providing excellent support to the operation of the IAC80 and Carlos Sánchez telescopes, and in particular to Álex Oscoz for a generous allocation of time to this project that proved to be essential to its success. We are also equally thankful to the staff of Calar Alto observatory for their support during our AstraLux observing run. The constructive remarks by an anonymous referee helped to improve the presentation of our results. NS acknowledges support by the French ANR and the German DFG through the project “GENESIS” (ANR-16-CE92-0035-01/DFG1591/2-1). This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.

O O O O O O O O O O B-Observatory I-Observatory I-Observatory O O O O O O O O B-Telescope O B-Telescope I-Telescope I-Telescope O O O O B-Person I-Person O O 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-Observatory I-Observatory I-Observatory O O O O O B-Instrument O O O O O O O O O O O O O O O O O B-Person O O O O B-Location B-Organization O O B-Location B-Organization O O B-Grant I-Grant B-Grant O O O O O O O O O B-Survey I-Survey I-Survey I-Survey I-Survey O O O O O O O B-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization


ACKNOWLEDGEMENTS We are grateful to the referee Anita Cochran whose comments improved the quality and clarity of this manuscript. The WHT is operated on the island of La Palma by the Isaac Newton Group of Telescopes in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. We gratefully thank the staff at the Isaac Newton Group for their support in the observations reported here. MGH acknowledges receipt of a Northern Ireland DEL studentship award. AF acknowledges support for this work from UK STFC grants ST/L000709/1 and ST/P0003094/1. CS acknowledges support from the STFC in the form of the Ernest Rutherford Fellowship.

O O O O O O O B-Person I-Person O O O O O O O O O O O B-Telescope O O O O B-Location I-Location I-Location I-Location O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Location B-Observatory I-Observatory I-Observatory I-Observatory I-Observatory I-Observatory O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O O B-Organization I-Organization I-Organization O O O O O O O O B-Person O O O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship B-Person O O O O O O B-Location B-Organization B-Grant I-Grant O B-Grant B-Person O O O O B-Organization O O O O O B-Fellowship I-Fellowship I-Fellowship


We thank the IRIS team for providing the data in the public domain. IRIS is a NASA small explorer mission developed and operated by LMSAL with mission operations executed at NASA Ames Research center and major contributions to downlink communications funded by the Norwegian Space Center (NSC, Norway) through an ESA PRODEX contract. H.T. is supported by contracts 8100002705 and SP02H1701R from Lockheed-Martin to SAO.

O O O B-Telescope O O O O O O O O O B-Telescope O O B-Organization B-Mission I-Mission I-Mission O O O O B-Organization O O O O O B-Organization I-Organization I-Organization I-Organization O O O O O O O O O B-Organization I-Organization I-Organization B-Organization B-Location O O B-Organization B-Grant I-Grant B-Person O O O B-Grant I-Grant O B-Grant O B-Organization O B-Observatory


O O B-Person I-Person O O O O O O O O O O B-Person I-Person O O O O O B-Organization I-Organization I-Organization I-Organization B-Organization B-Location O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-Location O B-Grant I-Grant O O B-Grant I-Grant O O O O O O O O O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility O B-Grant I-Grant I-Grant O B-Grant O O O O O O O B-Survey O O O O B-Survey O O O O O B-Organization B-Grant I-Grant O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O B-Organization I-Organization I-Organization I-Organization B-Grant I-Grant I-Grant I-Grant B-Grant I-Grant B-Grant I-Grant O B-Organization I-Organization I-Organization B-Organization O B-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization O B-Organization O O O O O O O B-Person I-Person O O O O O B-Organization I-Organization I-Organization I-Organization B-Person I-Person O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O O B-Grant I-Grant O O O O B-Organization I-Organization I-Organization I-Organization O O B-Grant I-Grant O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship O O O O O B-Grant I-Grant I-Grant I-Grant I-Grant O O O O O B-Organization I-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization B-Organization B-Person I-Person I-Person O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship B-Person O O O O O O O O B-Grant B-Grant B-Grant B-Grant O B-Grant O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O O B-Grant I-Grant O O B-Organization I-Organization I-Organization I-Organization B-Person I-Person I-Person B-Person I-Person O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Person I-Person O O O O B-Organization I-Organization O B-Grant I-Grant B-Person O B-Person O O O O B-Organization B-Grant I-Grant I-Grant B-Person O O O O O O B-Organization I-Organization I-Organization I-Organization O B-Grant I-Grant I-Grant O B-Grant I-Grant B-Person O O B-Fellowship I-Fellowship O O O B-Organization I-Organization I-Organization B-Grant I-Grant I-Grant B-Person I-Person I-Person O O O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship O B-Fellowship I-Fellowship O O B-Person I-Person O B-Person I-Person O O O O O O O O O O O O O O O B-Organization I-Organization I-Organization B-Organization B-Mission I-Mission O B-URL O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-URL O O O O B-Organization O O O O O O O O O O O O O B-Collaboration I-Collaboration I-Collaboration O O O O O B-Survey O O O O B-Organization B-Grant I-Grant I-Grant O O B-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization O B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization O B-Organization I-Organization I-Organization O B-Organization I-Organization I-Organization I-Organization O B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization I-Organization B-Organization I-Organization O O B-Observatory I-Observatory I-Observatory B-Survey O O O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O O O O B-Organization I-Organization I-Organization I-Organization O B-Survey O O O B-Observatory I-Observatory I-Observatory B-Observatory O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility B-ComputingFacility O O O O B-Survey O O O B-Observatory O O O O O O B-Organization I-Organization I-Organization B-Organization O O B-Organization I-Organization O O B-Grant I-Grant I-Grant I-Grant B-Grant O B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O O B-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility B-ComputingFacility O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization O O O O O O O O O B-Telescope I-Telescope I-Telescope I-Telescope O O O O O O O B-Organization I-Organization I-Organization B-Organization I-Organization O O B-Organization I-Organization I-Organization B-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O O O O B-Survey I-Survey I-Survey I-Survey I-Survey O O O O O O O B-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization I-Organization I-Organization O O O B-Organization I-Organization I-Organization I-Organization I-Organization O O B-Organization I-Organization I-Organization


Acknowledgements We thank the referee for their interesting and useful comments that helped improve the clarity of the paper. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory. F.B. acknowledges financial support from INAF through the “Progetti Premiali” funding scheme of the Italian Ministry of Education, University, and Research and through the ASI-INAF contract 2015-019-R.O. A.Z. acknowledges support from Prof. Giuseppe Lodato during his Master thesis work.

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-Observatory O O O B-Observatory I-Observatory I-Observatory I-Observatory B-Person O O O O B-Organization O O B-Grant I-Grant I-Grant I-Grant O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O B-Organization B-Grant I-Grant B-Person O O O B-Person I-Person I-Person O O O O O


We thank Alberto Sesana for illuminating discussions when starting this project, Phil Armitage for very useful comments on an earlier version of this paper, and Christoph Mordasini for fruitful discussions. We also thank students Gabriel Torrealba and Matías Gárate for their help in developing analysis and visualization tools for Fargo simulations. Financial support was provided by Millennium Nucleus RC130007 (Chilean Ministry of Economy). M.M. acknowledges support from FONDECYT grant No. 3120101 and CONICYT-Gemini grant No. 32130007, J.C. acknowledges support from CONICYTChile through FONDECYT (1141175), Basal (PFB0609), Anillo (ACT1101), and DRI-Intercambio (PCCI130064) grant, S.P. acknowledges financial support provided by FONDECYT grant 3140601, and S.C. acknowledges support from FONDECYT grant 1130949. The authors also thank the referee for suggestions that have improved the presentation of this paper.

O O B-Person I-Person O O O O O O O B-Person I-Person O O O O O O O O O O O O B-Person I-Person O O O O O O O B-Person I-Person O B-Person I-Person O O O O O O O O O O B-Model I-Model O O O O O B-Grant I-Grant I-Grant B-Organization I-Organization I-Organization I-Organization B-Person O O O B-Organization B-Grant I-Grant I-Grant O B-Organization B-Grant I-Grant I-Grant B-Person O O O B-Organization O B-Organization B-Grant B-Grant B-Grant B-Grant B-Grant O B-Organization B-Grant O B-Person O O O O O B-Organization B-Grant I-Grant O B-Person O O O B-Organization B-Grant I-Grant O O O O O O O O O O O O O O O O


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


The authors thank the referee, Marcin Sawicki, for a helpful report that improved this paper. D.M. would like to thank Giuseppe Longo, Audrey Galametz, Sotiria Fotopoulou, and George Helou for helpful conversations. D.M., P.C., D.S., and J.R. acknowledge support by NASA ROSES grant 12-EUCLID12-0004. J.R. and D.S. are supported by JPL, run by Caltech for NASA. F.C. acknowledges support by MINECO grant ESP2015-88861. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.

O O O O O B-Person I-Person O O O O O O O O B-Person O O O O B-Person I-Person B-Person I-Person B-Person I-Person O B-Person I-Person O O O B-Person B-Person B-Person O B-Person O O O B-Organization B-Grant I-Grant I-Grant B-Person O B-Person O O O B-Organization O O B-Organization O B-Organization B-Person O O O B-Organization O B-Grant O O O O O O O O O O O O O O O O O O B-Location I-Location O O O O O O B-Location O O O O O O O O O O O O O O O


ACKNOWLEDGEMENTS The authors would like to thank James Willis for his help with the velociraptor halo finder, and Aaron Ludlow, Cedric Lacey, Richard Bower, Shy Genel, Greg Bryan, and Rob Crain for helpful discussions that contributed significantly to this work. They would also like to thank the anonymous reviewer, who provided many useful suggestions that helped clarify our explanations. This work was initiated as a project for the Kavli Summer Program in Astrophysics held at the Center for Computational Astrophysics of the Flatiron Institute in 2018. The program was co-funded by the Kavli Foundation and the Simons Foundation. We thank them for their generous support. This work was supported by collaborative visits funded by the Cosmology and Astroparticle Student and Postdoc Exchange Network (CASPEN). JB is supported by Science and Technology Facilities Council (STFC) studentship ST/R504725/1. DAA is supported by the Flatiron Institute, which is supported by the Simons Foundation. This work used the ARCHER UK National Supercomputing Service. This work used the DiRAC@Durham facility managed by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility ( www.dirac.ac.uk ). The equipment was funded by BEIS capital funding via STFC capital grants ST/K00042X/1, ST/P002293/1, ST/R002371/1, and ST/S002502/1, Durham University, and STFC operations grant ST/R000832/1. DiRAC is part of the National e-Infrastructure. We would like to extend our thanks specifically to Alastair Basden and his team for managing the DiRAC Memory Intensive service. Software citations This paper made use of the following software packages: GIZMO (Hopkins 2017 ) gadget (Springel 2005 ) swift (Schaller et al. 2016 ) python (Rossum 1995 ), with the following libraries: numpy (Oliphant 2006 ) scipy (Jones et al. 2001 ) py-sphviewer (Benitez-Llambay 2015 ) caesar (Thompson 2018 ) yt (Turk et al. 2011 ) velociraptor (Elahi et al. 2019 ) The AHF (Gill et al. 2004 ; Knollmann Knebe 2009 ).

O O O O O O O B-Person I-Person O O O O O B-Software I-Software I-Software O B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person B-Person I-Person O B-Person I-Person O O O O O O O O O O O O O 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-Event I-Event I-Event I-Event I-Event O O O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization I-Organization O O O O O O O O B-Organization I-Organization O O B-Organization I-Organization O O O O O O O O O O O O O O O O O B-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship I-Fellowship B-Fellowship B-Person O O O B-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-Fellowship I-Fellowship B-Person O O O O B-Organization I-Organization O O O O O B-Organization I-Organization O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility O O O O B-ComputingFacility I-ComputingFacility O O O B-Organization I-Organization I-Organization I-Organization O O O O B-Organization B-ComputingFacility I-ComputingFacility I-ComputingFacility O B-URL O O O O O O B-Organization O O O B-Organization B-Grant I-Grant I-Grant B-Grant B-Grant O B-Grant B-Organization I-Organization O B-Organization B-Grant I-Grant I-Grant B-ComputingFacility O O O O B-ComputingFacility I-ComputingFacility O O O O O O O O O B-Person I-Person O O O O O O B-ComputingFacility I-ComputingFacility I-ComputingFacility I-ComputingFacility O O O O O O O O O O O B-Software B-Citation I-Citation O B-Software B-Citation I-Citation O B-Software B-Citation I-Citation I-Citation I-Citation O B-Software B-Citation I-Citation O O O O O B-Software B-Citation I-Citation O B-Software B-Citation I-Citation I-Citation I-Citation O B-Software B-Citation I-Citation O B-Software B-Citation I-Citation O B-Software B-Citation I-Citation I-Citation I-Citation O B-Software B-Citation I-Citation I-Citation I-Citation O B-Software I-Software B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation O


The authors thank an anonymous referee for the constructive and helpful comments. A. C. acknowledges funding from the Swiss National Science Foundation under grant P2GEP2_184492.

O O O O O O O O O O O O B-Person I-Person O O O O B-Organization I-Organization I-Organization I-Organization O B-Grant I-Grant


We acknowledge partial financial support from the Spanish Ministerio de Economía y Competitividad Project AYA2012-39475-C02-01 and Consolider-Ingenio 2010 CSD2010-00064. The authors thank Enrique Martínez-González for useful discussions and Francesco Paci for providing an apodisation code. The healp ix package (Górski et al. 2005 ) was used throughout the data analysis.

O O O O O O O B-Location B-Organization I-Organization I-Organization I-Organization I-Organization B-Grant I-Grant O B-Grant I-Grant I-Grant O O O B-Person I-Person O O O O B-Person I-Person O O O O O O B-Software I-Software I-Software B-Citation I-Citation I-Citation I-Citation O O O O O O O