On 17 August 2017, the Advanced LIGO(1) and Virgo(2) detectors observed the gravitational-wave event GW170817-a strong signal from the merger of a binary neutron-star system(3). Less than two seconds after the merger, a gamma-ray burst (GRB 170817A) was detected within a region of the sky consistent with the LIGO-Virgo-derived location of the gravitational-wave source(4-6). This sky region was subsequently observed by optical astronomy facilities(7), resulting in the identification(8-13) of an optical transient signal within about ten arcseconds of the galaxy NGC 4993. This detection of GW170817 in both gravitational waves and electromagnetic waves represents the first 'multi-messenger' astronomical observation. Such observations enable GW170817 to be used as a 'standard siren'(14-18) (meaning that the absolute distance to the source can be determined directly from the gravitational-wave measurements) to measure the Hubble constant. This quantity represents the local expansion rate of the Universe, sets the overall scale of the Universe and is of fundamental importance to cosmology. Here we report a measurement of the Hubble constant that combines the distance to the source inferred purely from the gravitational-wave signal with the recession velocity inferred from measurements of the redshift using the electromagnetic data. In contrast to previous measurements, ours does not require the use of a cosmic 'distance ladder'(19): the gravitational-wave analysis can be used to estimate the luminosity distance out to cosmological scales directly, without the use of intermediate astronomical distance measurements. We determine the Hubble constant to be about 70 kilometres per second per megaparsec. This value is consistent with existing measurements(20,21), while being completely independent of them. Additional standard siren measurements from future gravitational-wave sources will enable the Hubble constant to be constrained to high precision. ; United States National Science Foundation (NSF) Science and Technology Facilities Council (STFC) of the United Kingdom Max-Planck-Society (MPS) State of Niedersachsen/Germany Australian Research Council Netherlands Organisation for Scientific Research EGO consortium Council of Scientific and Industrial Research of India Department of Science and Technology, India Science and Engineering Research Board (SERB), India Ministry of Human Resource Development, India Spanish Agencia Estatal de Investigation Vicepresidencia i Conselleria d'Innovacio, Recerca i Turisme Conselleria d'Educacia i Universitet del Govern de les Illes Balears Conselleria d'Educacia, Investigacio, Culture i Esport de la Generalitat Valenciana National Science Centre of Poland Swiss National Science Foundation (SNSF) Russian Foundation for Basic Research Russian Science Foundation European Commission European Regional Development Funds (ERDF) Royal Society Scottish Funding Council Scottish Universities Physics Alliance Hungarian Scientific Research Fund (OTKA) Lyon Institute of Origins (LIO) National Research, Development and Innovation Office Hungary (NKFI) National Research Foundation of Korea, Industry Canada Province of Ontario through the Ministry of Economic Development and Innovation Natural Science and Engineering Research Council Canada Canadian Institute for Advanced Research Brazilian Ministry of Science, Technology, Innovations, and Communications International Center for Theoretical Physics South American Institute for Fundamental Research (ICTP-SAIFR) Research Grants Council of Hong Kong National Natural Science Foundation of China (NSFC) Leverhulme Trust Research Corporation Ministry of Science and Technology (MOST), Taiwan Kavli Foundation NSF STFC MPS INFN CNRS Danish National Research Foundation Niels Bohr International Academy DARK Cosmology Centre NSF AST-1518052 AST-1411763 AST-1714498 AST -1138766 AST-1536171 AST-1517649 AST-1313484 Gordon & Betty Moore Foundation Heising-Simons Foundation UCSC Giving Day grant Alfred P. Sloan Foundation David and Lucile Packard Foundation Niels Bohr Professorship from the DNRF UCMEXUS-CONACYT Doctoral Fellowship NASA through Hubble Fellowship - Space Telescope Science Institute HST-HF-51348.001 HST-HF-51373.001 NASA NAS5-26555 NNX15AE50G NNX16AC22G DOE (USA) NSF (USA) MEC/MICINN/MINECO (Spain) STFC (UK) HEFCE (UK) NCSA (UIUC) KICP (U. Chicago) CCAPP (Ohio State) MIFPA (Texas AM) CNPQ (Brazil) FAPERJ (Brazil) FINEP (Brazil) DFG (Germany) Argonne Lab UC Santa Cruz University of Cambridge Dark Energy Survey CIEMAT-Madrid University of Chicago University College London DES-Brazil Consortium University of Edinburgh ETH Zurich Fermilab University of Illinois ICE (IEEC-CSIC) IFAE Barcelona Lawrence Berkeley Lab LMU Munchen associated Excellence Cluster Universe University of Michigan NOAO University of Nottingham Ohio State University University of Pennsylvania University of Portsmouth SLAC National Lab Stanford University University of Sussex Texas AM University OzDES Membership Consortium MINECO AYA2015-71825 ESP2015-88861 FPA2015-68048 Centro de Excelencia SEV-2012-0234 SEV-2016-0597 MDM-2015-0509 ERC under the European Union's Seventh Framework Programme ERC 240672 291329 306478 Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO) CE110001020 US Department of Energy, Office of Science, Office of High Energy Physics DE-AC02-07CH11359 NASA through the Einstein Fellowship Program PF6-170148 Israel Science Foundation 541/17
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of similar to 1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg(2) at a luminosity distance of 40(-8)(+8) Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 M-circle dot. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at similar to 40 Mpc) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over similar to 10 days. Following early non-detections, X-ray and radio emission were discovered at the transient's position similar to 9 and similar to 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta. ; Kavli Foundation; Danish National Research Foundation; Niels Bohr International Academy; DARK Cosmology Centre; NSF [AST-1518052, AST-141242, AST-1411763, AST-1714498, AST-1517649, PHY-1607291, AST-1412421, AST-1313484]; Gordon AMP; Betty Moore Foundation; Heising-Simons Foundation; Alfred P. 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Istituto Nazionale di Fisica Nucleare (INFN), Italy; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation, Russia; National Authority for Scientific Research (ANCS), Romania; Ministerio de Economia y Competitividad (MINECO): Plan Estatal de Investigacion (MINECO/FEDER), Spain [FPA2015-65150-C3-1-P, FPA2015-65150-C3-2-P, FPA2015-65150-C3-3-P]; Severo Ochoa Centre of Excellence and MultiDark Consolider (MINECO), Spain; Prometeo program (Generalitat Valenciana), Spain; Grisolia program (Generalitat Valenciana), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco; National Basic Research Program (973 Program) of China [2013CB834901, 2013CB834900, 2013CB834903]; Chinese Polar Environment Comprehensive Investigation AMP; Assessment Program [CHINARE2016-02-03-05]; Tsinghua University; Nanjing University; Beijing Normal University; University of New South Wales; Texas AM University; 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[Dnr. 2016-06012]; Science and Engineering Research Board, Department of Science and Technology, India; Indo-US Science and Technology Foundation; US National Science Foundation (NSF); US Department of Energy Office of High-Energy Physics; Laboratory Directed Research and Development (LDRD) program of Los Alamos National Laboratory; Consejo Nacional de Ciencia y Tecnologia (CONACyT), Mexico [271051, 232656, 167281, 260378, 179588, 239762, 254964, 271737, 258865, 243290]; Red HAWC, Mexico; DGAPA-UNAM [RG100414, IN111315, IN111716-3, IA102715, 109916]; VIEP-BUAP; University of Wisconsin Alumni Research Foundation; Institute of Geophysics, Planetary Physics, and Signatures at Los Alamos National Laboratory; Polish Science Centre [DEC-2014/13/B/ST9/945]; German Ministry for Education and Research (BMBF); Max Planck Society; German Research Foundation (DFG); Alexander von Humboldt Foundation; Deutsche Forschungsgemeinschaft; French Ministry for Research; CNRS-IN2P3; Astroparticle Interdisciplinary Programme of the CNRS; 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Science and Education Ministry of Kazakhstan [0075/GF4]; RUSTAVELI [FR/379/6-300/14]; ESA Denmark; ESA France; ESA Germany; ESA Italy; ESA Switzerland; ESA Spain; ESA Russia; ESA USA; CEA; CNES; DLR; ESA; INTA; OSTC; ASI/INAF [2013-025-R.1]; German INTEGRAL through DLR [50 OG 1101]; Spanish MINECO/FEDER [ESP2015-65712-C5-1-R]; RFBR [16-29-13009-ofi-m]; JSPS KAKENHI [JP16H02183, JP15H02075, JP15H02069, JP26800103, JP25800103]; Inter-University Cooperation Program of the MEXT; NINS program; Toyota Foundation [D11-R-0830]; Mitsubishi Foundation; Yamada Science Foundation; Inoue Foundation for Science; National Research Foundation of South Africa; NRF [2017R1A3A3001362]; KASI [2017-1-830-03]; Israel Science Foundation [541/17]; Council of Scientific and Industrial Research of India; Department of Science and Technology, India; Science AMP; Engineering Research Board (SERB), India; Ministry of Human Resource Development, India; Spanish Agencia Estatal de Investigacion; Vicepresidencia i Conselleria d'Innovacio Recerca i Turisme; Conselleria d'Educacio i Universitat del Govern de les Illes Balears; Conselleria d'Educacio Investigacio Cultura i Esport de la Generalitat Valenciana; National Science Centre of Poland; Swiss National Science Foundation (SNSF); Russian Foundation for Basic Research; Russian Science Foundation; European Commission; European Regional Development Funds (ERDF); Royal Society; Scottish Funding Council; Scottish Universities Physics Alliance; Hungarian Scientific Research Fund (OTKA); Lyon Institute of Origins (LIO); National Research, Development and Innovation Office Hungary (NKFI); National Research Foundation of Korea; Industry Canada and Province of Ontario through Ministry of Economic Development and Innovation; Natural Science and Engineering Research Council Canada; Canadian Institute for Advanced Research; Brazilian Ministry of Science, Technology, Innovations, and Communications; International Center for Theoretical Physics South American Institute for Fundamental Research (ICTP-SAIFR); Council of Hong Kong; National Natural Science Foundation of China (NSFC); Chinese Academy of Sciences (CAS); Ministry of Science and Technology of China (MOST); Leverhulme Trust; Research Corporation; Ministry of Science and Technology (MOST), Taiwan; RIKEN; MEXT; KAKENHI [JP 17H06362]; EVN [RP029]; European Union's Horizon 2020 research and innovation programme [653477]; ERC [647208]; Netherlands Organization for Scientific Research through NWO VIDI [639.042.612-Nissanke]; NWO TOP [62002444-Nissanke]; VISIR [60.A-9392]; [MOST104-2923-M-008-004-MY5]; [MOST106-2112-M-008-007] ; (1M2H) We thank J. McIver for alerting us to the LVC circular. We thank J. Mulchaey (Carnegie Observatories director), L. Infante (Las Campanas Observatory director), and the entire Las Campanas staff for their extreme dedication, professionalism, and excitement, all of which were critical in the discovery of the first gravitational-wave optical counterpart and its host galaxy as well as the observations used in this study. We thank I. Thompson and the Carnegie Observatory Time Allocation Committee for approving the Swope Supernova Survey and scheduling our program. We thank the University of Copenhagen, DARK Cosmology Centre, and the Niels Bohr International Academy for hosting D.A.C., R.J.F., A.M.B., E.R., and M.R.S. during the discovery of GW170817/SSS17a. R.J.F., A.M.B., and E.R. were participating in the Kavli Summer Program in Astrophysics, "Astrophysics with gravitational wave detections." This program was supported by the the Kavli Foundation, Danish National Research Foundation, the Niels Bohr International Academy, and the DARK Cosmology Centre. The UCSC group is supported in part by NSF grant AST-1518052, the Gordon & Betty Moore Foundation, the Heising-Simons Foundation, generous donations from many individuals through a UCSC Giving Day grant, and from fellowships from the Alfred P. Sloan Foundation (R.J.F.), the David and Lucile Packard Foundation (R.J.F. and E.R.) and the Niels Bohr Professorship from the DNRF (E.R.). AMB acknowledges support from a UCMEXUS-CONACYT Doctoral Fellowship. Support for this work was provided by NASA through Hubble Fellowship grants HST-HF-51348.001 (B.J.S.) and HST-HF-51373.001 (M.R.D.) awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. This paper includes data gathered with the 1 meter Swope and 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.r (AGILE) The AGILE Team thanks the ASI management, the technical staff at the ASI Malindi ground station, the technical support team at the ASI Space Science Data Center, and the Fucino AGILE Mission Operation Center. 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. We also thank INAF, Italian Institute of Astrophysics, and ASI, Italian Space Agency.r (ANTARES) The ANTARES Collaboration acknowledges the financial support of: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'energie atomique et aux energies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02), Labex OCEVU (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cite d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; National Authority for Scientific Research (ANCS), Romania; Ministerio de Economia y Competitividad (MINECO): Plan Estatal de Investigacion (refs.; r r FPA2015-65150-C3-1-P, -2-P and -3-P; MINECO/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider (MINECO), and Prometeo and Grisolia programs (Generalitat Valenciana), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities.r (AST3) The AST3 project is supported by the National Basic Research Program (973 Program) of China (Grant Nos. 2013CB834901, 2013CB834900, 2013CB834903), and the Chinese Polar Environment Comprehensive Investigation & Assessment Program (grant No. CHINARE2016-02-03-05). The construction of the AST3 telescopes has received fundings from Tsinghua University, Nanjing University, Beijing Normal University, University of New South Wales, and Texas A&M University, the Australian Antarctic Division, and the National Collaborative Research Infrastructure Strategy (NCRIS) of Australia. It has also received funding from Chinese Academy of Sciences through the Center for Astronomical Mega-Science and National Astronomical Observatory of China (NAOC).r (Auger) The successful installation, commissioning, and operation of the Pierre Auger Observatory would not have been possible without the strong commitment and effort from the technical and administrative staff in Malargue. We are very grateful to the following agencies and organizations for financial support: Argentina-Comision Nacional de Energia Atomica; Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET); Gobierno de la Provincia de Mendoza; Municipalidad de Malargue; NDM Holdings and Valle Las Lenas; in gratitude for their continuing cooperation over land access; Australia-the Australian Research Council; Brazil-Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Financiadora de Estudos e Projetos (FINEP); Fundacao de Amparo a Pesquisa do Estado de Rio de Janeiro (FAPERJ); Sao Paulo Research Foundation (FAPESP) grant Nos. 2010/07359-6 and 1999/05404-3; Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (MCTIC); Czech Republic-grant Nos. MSMT CR LG15014, LO1305, LM2015038 and CZ.02.1.01/0.0/0.0/16_013/0001402; France-Centre de Calcul IN2P3/CNRS; Centre National de la Recherche Scientifique (CNRS); Conseil Regional Ile-de-France; Departement Physique Nucleaire et Corpusculaire (PNC-IN2P3/CNRS); Departement Sciences de l'Univers (SDU-INSU/CNRS); Institut Lagrange de Paris (ILP) grant No. LABEX ANR-10-LABX-63 within the Investissements d'Avenir Programme Grant No. ANR-11-IDEX-0004-02; Germany-Bundesministerium fur Bildung und Forschung (BMBF); Deutsche Forschungsgemeinschaft (DFG); Finanzministerium Baden-Wurttemberg; Helmholtz Alliance for Astroparticle Physics (HAP); Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF); Ministerium fur Innovation, Wissenschaft und Forschung des Landes Nordrhein-Westfalen; Ministerium fur Wissenschaft, Forschung und Kunst des Landes Baden-Wurttemberg; Italy-Istituto Nazionale di Fisica Nucleare (INFN); Istituto Nazionale di Astrofisica (INAF); Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR); CETEMPS Center of Excellence; Ministero degli Affari Esteri (MAE); Mexico-Consejo Nacional de Ciencia y Tecnologia (CONACYT) No.; r r 167733; Universidad Nacional Autonoma de Mexico (UNAM); PAPIIT DGAPA-UNAM; The Netherlands - Ministerie van Onderwijs, Cultuur en Wetenschap; Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO); Stichting voor Fundamenteel Onderzoek der Materie (FOM); Poland-National Centre for Research and Development, grant Nos. ERA-NET-ASPERA/01/11 and ERA-NET-ASPERA/02/11; National Science Centre, grant Nos. 2013/08/M/ST9/00322, 2013/08/M/ST9/00728, and HARMONIA 5-2013/10/M/ST9/00062, UMO-2016/22/M/ST9/00198; Portugal-Portuguese national funds and FEDER funds within Programa Operacional Factores de Competitividade through Fundacao para a Ciencia e a Tecnologia (COMPETE); Romania-Romanian Authority for Scientific Research ANCS; CNDI-UEFISCDI partnership projects grant Nos. 20/2012 and 194/2012 and PN 16 42 01 02; Slovenia-Slovenian Research Agency; Spain-Comunidad de Madrid; Fondo Europeo de Desarrollo Regional (FEDER) funds; Ministerio de Economia y Competitividad; Xunta de Galicia; European Community 7th Framework Program grant No. FP7-PEOPLE-2012-IEF-328826; USA-Department of Energy, Contract Nos. DE-AC02-07CH11359, DE-FR02-04ER41300, DE-FG02-99ER41107, and DE-SC0011689; National Science Foundation, grant No.r 0450696; The Grainger Foundation; Marie Curie-IRSES/EPLANET; European Particle Physics Latin American Network; European Union 7th Framework Program, grant No. PIRSES-2009-GA-246806; European Union's Horizon 2020 research and innovation programme (grant No. 646623); and UNESCO.r (Australian Radio) T.M. acknowledges the support of the Australian Research Council through grant FT150100099. S.O. acknowledges the Australian Research Council grant Laureate Fellowship FL15010014. D.L.K. and I.S.B. are additionally supported by NSF grant AST-141242. P.A.B. and the DFN team acknowledge the Australian Research Council for support under their Australian Laureate Fellowship scheme. The Australia Telescope Compact Array is part of the Australia Telescope National Facility, which is funded by the Australian Government for operation as a National Facility managed by CSIRO. This scientific work makes use of the Murchison Radio-astronomy Observatory, operated by CSIRO. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site. Support for the operation of the MWA is provided by the Australian Government (NCRIS), under a contract to Curtin University administered by Astronomy Australia Limited. We acknowledge the Pawsey Supercomputing Centre, which is supported by the Western Australian and Australian Governments. The Australian SKA Pathfinder is part of the Australia Telescope National Facility, which is managed by CSIRO. Operation of ASKAP is funded by the Australian Government with support from the National Collaborative Research Infrastructure Strategy. ASKAP uses the resources of the Pawsey Supercomputing Centre. Establishment of ASKAP, the Murchison Radio-astronomy Observatory and the Pawsey Supercomputing Centre are initiatives of the Australian Government, with support from the Government of Western Australia and the Science and Industry Endowment Fund. Parts of this research were conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics in 3D (ASTRO 3D) through project number CE170100013.r (Berger Time-Domain Group) The Berger Time-Domain Group at Harvard is supported in part by the NSF through grants AST-1411763 and AST-1714498, and by NASA through grants NNX15AE50G and NNX16AC22G.r (Bootes) A.J.C.T.; r r acknowledges support from the Spanish Ministry Project AYA 2015-71718-R (including FEDER funds) and Junta de Andalucia Proyecto de Excelencia TIC-2839. I.H.P. acknowledges the support of the National Research Foundation (NRF-2015R1A2A1A01006870). S.J. acknowledges the support of Korea Basic Science Research Program (NRF2014R1A6A3A03057484 and NRF-2015R1D1A4A01020961). The BOOTES-5/JGT observations were carried out at Observatorio Astronomico Nacional in San Pedro Martir (OAN-SPM, Mexico), operated by Instituto de Astronomia, UNAM and with support from Consejo Nacional de Ciencia y Tecnologia (Mexico) through the Laboratorios Nacionales Program (Mexico), Instituto de Astrofisica de Andalucia (IAA-CSIC, Spain) and Sungkyunkwan University (SKKU, South Korea). We also thank the staff of OAN-SPM for their support in carrying out the observations.r (CAASTRO) Parts of this research were conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020. The national facility capability for SkyMapper has been funded through ARC LIEF grant LE130100104 from the Australian Research Council, awarded to the University of Sydney, the Australian National University, Swinburne University of Technology, the University of Queensland, the University of Western Australia, the University of Melbourne, Curtin University of Technology, Monash University, and the Australian Astronomical Observatory. SkyMapper is owned and operated by The Australian National University's Research School of Astronomy and Astrophysics.r (CALET) The CALET team gratefully acknowledges support from NASA, ASI, JAXA, and MEXT KAKENHI grant numbers JP 17H06362, JP26220708, and JP17H02901.r (Chandra/McGill) This work was supported in part by Chandra Award Number GO7-18033X, issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration (NASA) under contract NAS8-03060. D.H., M.N., and J.J.R. acknowledge support from a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant and a Fonds de recherche du Quebec-Nature et Technologies (FRQNT) Nouveaux Chercheurs Grant. P.A.E. acknowledges UKSA support. J.A.K. acknowledges the support of NASA grant NAS5-00136. D.H. also acknowledges support from the Canadian Institute for Advanced Research (CIFAR).r (CZTI/AstroSat) CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.r (DLT40) D.J.S. acknowledges support for the DLT40 program from NSF grant AST-1517649.r (EuroVLBI) The European VLBI Network is a joint facility of independent European, African, Asian, and North American radio astronomy institutes. Scientific results from data presented in this publication are derived from the following EVN project code: RP029. e-MERLIN is a National Facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of STFC. The collaboration between LIGO/Virgo and EVN/e-MERLIN is part of a project that has received funding from the European Unions Horizon 2020 research and innovation programme under grant agreement No. 653477.r (ePESSTO) We acknowledge ESO programs 199.D-0143 and 099.D-0376. PS1 and ATLAS are supported by NASA grants NNX08AR22G, NNX12AR65G, NNX14AM74G, and NNX12AR55G. We acknowledge the Leibniz-Prize to Prof. G.; r r Hasinger (DFG grant HA 1850/28-1), EU/FP7-ERC grants 291222, 615929, 647208, 725161, STFC grants ST/P000312/1 and ERF ST/M005348/1, ST/P000495/1. Marie Sklodowska-Curie grant No 702538. Polish NCN grant OPUS 2015/17/B/ST9/03167, Knut and Alice Wallenberg Foundation. PRIN-INAF 2014. David and Ellen Lee Prize Postdoctoral Fellowship at the California Institute of Technology. Alexander von Humboldt Sofja Kovalevskaja Award. Royal Society-Science Foundation Ireland Vilho, Yrjo and Kalle Vaisala Foundation. FONDECYT grant number 3160504. US NSF grant AST-1311862. Swedish Research Council and the Swedish Space Board. The Quantum Universe I-Core program, the ISF, BSF, and Kimmel award. IRC grant GOIPG/2017/1525. Australian Research Council CAASTRO CE110001020 and grant FT160100028. We acknowledge Millennium Science Initiative grant IC120009.r (Fermi-GBM) B.C., V.C., A.G., and W.S.P. gratefully acknowledge NASA funding through contract NNM13AA43C. M.S.B., R.H., P.J., C.A.M., S.P., R.D.P., M.S., and P.V. gratefully acknowledge NASA funding from cooperative agreement NNM11AA01A. E.B. is supported by an appointment to the NASA Postdoctoral Program at the Goddard Space Flight Center, administered by Universities Space Research Association under contract with NASA. D.K., C.A.W.H., C.M.H., and J.R. gratefully acknowledge NASA funding through the Fermi-GBM project. Support for the German contribution to GBM was provided by the Bundesministerium fur Bildung und Forschung (BMBF) via the Deutsches Zentrum fur Luft und Raumfahrt (DLR) under contract number 50 QV 0301. A.v.K. was supported by the Bundesministeriums fur Wirtschaft und Technologie (BMWi) through DLR grant 50 OG 1101. S.M.B. acknowledges support from Science Foundation Ireland under grant 12/IP/1288.r (Fermi-LAT) The Fermi-LAT Collaboration acknowledges support for LAT development, operation, and data analysis from NASA and DOE (United States), CEA/Irfu and IN2P3/CNRS (France), ASI and INFN (Italy), MEXT, KEK, and JAXA (Japan), and the K. A. Wallenberg Foundation, the Swedish Research Council and the National Space Board (Sweden). Science analysis support in the operations phase from INAF (Italy) and CNES (France) is also gratefully acknowledged. This work performed in part under DOE Contract DE-AC02-76SF00515.r (FRBSG) S.L.L. is supported by NSF grant PHY-1607291 (LIU). Construction of the LWA has been supported by the Office of Naval Research under Contract N00014-07-C0147. Support for operations and continuing development of the LWA1 is provided by the National Science Foundation under grants AST-1139963 and AST-1139974 of the University Radio Observatory program.r (GRAWITA) We acknowledge INAF for supporting the project "Gravitational Wave Astronomy with the first detections of adLIGO and adVIRGO experiments-GRAWITA" PI: E. Brocato. Observations are made with ESO Telescopes at the Paranal Observatory under programmes ID 099.D-0382 (PI: E. Pian), 099.D-0622 (PI: P. D'Avanzo), 099.D-0191 (PI: A. Grado), 099.D-0116 (PI: S. Covino) and with the REM telescope at the ESO La Silla Observatory under program ID 35020 (PI: S. Campana). We thank the ESO operation staff for excellent support of this program. The Sardinia Radio Telescope (SRT) is funded by the Department of University and Research (MIUR), the Italian Space Agency (ASI), and the Autonomous Region of Sardinia (RAS) and is operated as National Facility by the National Institute for Astrophysics (INAF). Z.J. is supported by the External Cooperation Program of BIC (number 114332KYSB20160007). J.M.; r r is supported by the Hundred Talent Program, the Major Program of the Chinese Academy of Sciences (KJZD-EW-M06), the National Natural Science Foundation of China 11673062, and the Oversea Talent Program of Yunnan Province. R.L.C. Starling, K.W., A.B.H., N.R.T., and C.G.M. are supported by the STFC (Science and Technology Facilities Council). D.K., acknowledges the financial support from the Slovenian Research Agency (P1-0188). S.K. and A.N.G. acknowledge support by grant DFG Kl 766/16-3. D.G. acknowledges the financial support of the UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02). K.T. was supported by JSPS grant 15H05437 and by a JST Consortia grant.r (GROND) Part of the funding for GROND was generously granted from the Leibniz-Prize to Prof. G. Hasinger (DFG grant HA 1850/28-1). "We acknowledge the excellent help in obtaining GROND data from Angela Hempel, Markus Rabus and Regis Lachaume on La Silla."r (GROWTH, JAGWAR, Caltech-NRAO, TTU-NRAO, and NuSTAR) This work was supported by the GROWTH (Global Relay of Observatories Watching Transients Happen) project funded by the National Science Foundation under PIRE grant No. 1545949. GROWTH is a collaborative project among California Institute of Technology (USA), University of Maryland College Park (USA), University of Wisconsin-Milwaukee (USA), Texas Tech University (USA), San Diego State University (USA), Los Alamos National Laboratory (USA), Tokyo Institute of Technology (Japan), National Central University (Taiwan), Indian Institute of Astrophysics (India), Inter-University Center for Astronomy and Astrophysics (India), Weizmann Institute of Science (Israel), The Oskar Klein Centre at Stockholm University (Sweden), Humboldt University (Germany), Liverpool John Moores University (UK). A.H. acknowledges support by the I-Core Program of the Planning and Budgeting Committee and the Israel Science Foundation. T.M. acknowledges the support of the Australian Research Council through grant FT150100099. Parts of this research were conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020. The Australia Telescope Compact Array is part of the Australia Telescope National Facility which is funded by the Australian Government for operation as a National Facility managed by CSIRO. D.L.K. is additionally supported by NSF grant AST-1412421. A.A.M. is funded by the Large Synoptic Survey Telescope Corporation in support of the Data Science Fellowship Program. P.C.Y., C.C.N., and W.H.I. thank the support from grants MOST104-2923-M-008-004-MY5 and MOST106-2112-M-008-007. A.C. acknowledges support from the National Science Foundation CAREER award 1455090, "CAREER: Radio and gravitational-wave emission from the largest explosions since the Big Bang." T.P. acknowledges the support of Advanced ERC grant TReX. B.E.C. thanks SMARTS 1.3 m Queue Manager Bryndis Cruz for prompt scheduling of the SMARTS observations. Basic research in radio astronomy at the Naval Research Laboratory (NRL) is funded by 6.1 Base funding. Construction and installation of VLITE was supported by NRL Sustainment Restoration and Maintenance funding. K.P.M.'s research is supported by the Oxford Centre for Astrophysical Surveys, which is funded through the Hintze Family Charitable Foundation. J.S. and A.G. are grateful for support from the Knut and Alice Wallenberg Foundation. GREAT is funded by the Swedish Research Council (V.R.). E.O.O.; r r is grateful for the support by grants from the Israel Science Foundation, Minerva, Israeli ministry of Science, the US-Israel Binational Science Foundation, and the I-CORE Program of the Planning and Budgeting Committee and The Israel Science Foundation. We thank the staff of the GMRT that made these observations possible. The GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research. AYQH was supported by a National Science Foundation Graduate Research Fellowship under grant No. DGE-1144469. S.R. has been supported by the Swedish Research Council (VR) under grant number 2016 03657 3, by the Swedish National Space Board under grant number Dnr. 107/16 and by the research environment grant "Gravitational Radiation and Electromagnetic Astrophysical Transients (GREAT)" funded by the Swedish Research council (V.R.) under Dnr. 2016-06012.r We acknowledge the support of the Science and Engineering Research Board, Department of Science and Technology, India and the Indo-US Science and Technology Foundation for the GROWTH-India project.r (HAWC) We acknowledge the support from: the US National Science Foundation (NSF); the US Department of Energy Office of High-Energy Physics; the Laboratory Directed Research and Development (LDRD) program of Los Alamos National Laboratory; Consejo Nacional de Ciencia y Tecnologia (CONACyT), Mexico (grants 271051, 232656, 167281, 260378, 179588, 239762, 254964, 271737, 258865, 243290); Red HAWC, Mexico; DGAPA-UNAM (grants RG100414, IN111315, IN111716-3, IA102715, 109916); VIEP-BUAP; the University of Wisconsin Alumni Research Foundation; the Institute of Geophysics, Planetary Physics, and Signatures at Los Alamos National Laboratory; Polish Science Centre grant DEC-2014/13/B/ST9/945. We acknowledge the support of the Science and Engineering Research Board, Department of Science and Technology, India and the Indo-US Science and Technology Foundation for the GROWTH-India project.r (H.E.S.S.) The support of the Namibian authorities and of the University of Namibia in facilitating the construction and operation of H.E.S.S. is gratefully acknowledged, as is the support by the German Ministry for Education and Research (BMBF), the Max Planck Society, the German Research Foundation (DFG), the Alexander von Humboldt Foundation, the Deutsche Forschungsgemeinschaft, the French Ministry for Research, the CNRS-IN2P3 and the Astroparticle Interdisciplinary Programme of the CNRS, the U.K. Science and Technology Facilities Council (STFC), the IPNP of the Charles University, the Czech Science Foundation, the Polish National Science Centre, the South African Department of Science and Technology and National Research Foundation, the University of Namibia, the National Commission on Research, Science and Technology of Namibia (NCRST), the Innsbruck University, the Austrian Science Fund (FWF), and the Austrian Federal Ministry for Science, Research and Economy, the University of Adelaide and the Australian Research Council, the Japan Society for the Promotion of Science and by the University of Amsterdam. We appreciate the excellent work of the technical support staff in Berlin, Durham, Hamburg, Heidelberg, Palaiseau, Paris, Saclay, and in Namibia in the construction and operation of the equipment. This work benefited from services provided by the H.E.S.S. Virtual Organisation, supported by the national resource providers of the EGI Federation.; r r r (Insight-HXMT) The Insight-HXMT team acknowledges the support from the China National Space Administration (CNSA), the Chinese Academy of Sciences (CAS; grant No. XDB23040400), and the Ministry of Science and Technology of China (MOST; grant No. 2016YFA0400800).r (IceCube) We acknowledge the support from the following agencies: U.S. National Science Foundation-Office of Polar Programs, U.S. National Science Foundation-Physics Division, University of Wisconsin Alumni Research Foundation, the Grid Laboratory of Wisconsin (GLOW) grid infrastructure at the University of Wisconsin-Madison, the Open Science Grid (OSG) grid infrastructure; U.S. Department of Energy, and National Energy Research Scientific Computing Center, the Louisiana Optical Network Initiative (LONI) grid computing resources; Natural Sciences and Engineering Research Council of Canada, WestGrid and Compute/Calcul Canada; Swedish Research Council, Swedish Polar Research Secretariat, Swedish National Infrastructure for Computing (SNIC), and Knut and Alice Wallenberg Foundation, Sweden; German Ministry for Education and Research (BMBF), Deutsche Forschungsgemeinschaft (DFG), Helmholtz Alliance for Astroparticle Physics (HAP), Initiative and Networking Fund of the Helmholtz Association, Germany; Fund for Scientific Research (FNRS-FWO), FWO Odysseus programme, Flanders Institute to encourage scientific and technological research in industry (IWT), Belgian Federal Science Policy Office (Belspo); Marsden Fund, New Zealand; Australian Research Council; Japan Society for Promotion of Science (JSPS); the Swiss National Science Foundation (SNSF), Switzerland; National Research Foundation of Korea (NRF); Villum Fonden, Danish National Research Foundation (DNRF), Denmark.r (IKI-GW) A.S.P., A.A.V., E.D.M., and P.Y.u.M. acknowledge the support from the Russian Science Foundation (grant 15-1230015). V.A.K., A.V.K., and I.V.R. acknowledge the Science and Education Ministry of Kazakhstan (grant No. 0075/GF4). R.I. is grateful to the grant RUSTAVELI FR/379/6-300/14 for partial support. We acknowledge the excellent help in obtaining Chilescope data from Sergei Pogrebsskiy and Ivan Rubzov.r (INTEGRAL) This work is based on observations with INTEGRAL, an ESA project with instruments and science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), and with the participation of Russia and the USA. The INTEGRAL SPI project has been completed under the responsibility and leadership of CNES. The SPI-ACS detector system has been provided by MPE Garching/Germany. The SPI team is grateful to ASI, CEA, CNES, DLR, ESA, INTA, NASA, and OSTC for their support. The Italian INTEGRAL team acknowledges the support of ASI/INAF agreement No. 2013-025-R.1. R.D. and A.v.K. acknowledge the German INTEGRAL support through DLR grant 50 OG 1101. A.L. and R.S. acknowledge the support from the Russian Science Foundation (grant 14-22-00271). A.D. is funded by Spanish MINECO/FEDER grant ESP2015-65712-C5-1-R.r (IPN) K.H. is grateful for support under NASA grant NNX15AE60G. R.L.A. and D.D.F. are grateful for support under RFBR grant 16-29-13009-ofi-m.; r r r (J-GEM) MEXT KAKENHI (JP17H06363, JP15H00788, JP24103003, JP10147214, JP10147207), JSPS KAKENHI (JP16H02183, JP15H02075, JP15H02069, JP26800103, JP25800103), Inter-University Cooperation Program of the MEXT, the NINS program for cross-disciplinary science study, the Toyota Foundation (D11-R-0830), the Mitsubishi Foundation, the Yamada Science Foundation, Inoue Foundation for Science, the National Research Foundation of South Africa.r (KU) The Korea-Uzbekistan Consortium team acknowledges the support from the NRF grant No. 2017R1A3A3001362, and the KASI grant 2017-1-830-03. This research has made use of the KMTNet system operated by KASI.r (Las Cumbres) Support for I. A. and J.B. was provided by NASA through the Einstein Fellowship Program, grants PF6-170148 and PF7-180162, respectively. D.A.H., C.M., and G.H. are supported by NSF grant AST-1313484. D.P. and D.M acknowledge support by Israel Science Foundation grant 541/17. This work makes use of observations from the LCO network.r (LIGO and Virgo) The authors gratefully acknowledge the support of the United States National Science Foundation (NSF) for the construction and operation of the LIGO Laboratory and Advanced LIGO as well as the Science and Technology Facilities Council (STFC) of the United Kingdom, the Max-Planck- Society (MPS), and the State of Niedersachsen/Germany for support of the construction of Advanced LIGO and construction and operation of the GEO600 detector. Additional support for advanced LIGO was provided by the Australian Research Council. The authors gratefully acknowledge the Italian Istituto Nazionale di Fisica Nucleare (INFN), the French Centre National de la Recherche Scientifique (CNRS) and the Foundation for Fundamental Research on Matter supported by the Netherlands Organisation for Scientific Research, for the construction and operation of the Virgo detector and the creation and support of the EGO consortium.; r r The authors also gratefully acknowledge research support from these agencies as well as by the Council of Scientific and Industrial Research of India, the Department of Science and Technology, India, the Science & Engineering Research Board (SERB), India, the Ministry of Human Resource Development, India, the Spanish Agencia Estatal de Investigacion, the Vicepresidencia i Conselleria d'Innovacio Recerca i Turisme and the Conselleria d'Educacio i Universitat del Govern de les Illes Balears, the Conselleria d'Educacio Investigacio Cultura i Esport de la Generalitat Valenciana, the National Science Centre of Poland, the Swiss National Science Foundation (SNSF), the Russian Foundation for Basic Research, the Russian Science Foundation, the European Commission, the European Regional Development Funds (ERDF), the Royal Society, the Scottish Funding Council, the Scottish Universities Physics Alliance, the Hungarian Scientific Research Fund (OTKA), the Lyon Institute of Origins (LIO), the National Research, Development and Innovation Office Hungary (NKFI), the National Research Foundation of Korea, Industry Canada and the Province of Ontario through the Ministry of Economic Development and Innovation, the Natural Science and Engineering Research Council Canada, the Canadian Institute for Advanced Research, the Brazilian Ministry of Science, Technology, Innovations, and Communications, the International Center for Theoretical Physics South American Institute for Fundamental Research (ICTP-SAIFR), the Research Grants Council of Hong Kong, the National Natural Science Foundation of China (NSFC), the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS), the Ministry of Science and Technology of China (MOST), the Leverhulme Trust, the Research Corporation, the Ministry of Science and Technology (MOST), Taiwan and the Kavli Foundation. The authors gratefully acknowledge the support of the NSF, STFC, MPS, INFN, CNRS, and the State of Niedersachsen/Germany for provision of computational resources. The MAXI team acknowledges the support by JAXA, RIKEN, and MEXT KAKENHI grant number JP 17H06362. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The European VLBI Network is a joint facility of independent European, African, Asian, and North American radio astronomy institutes. Scientific results from data presented in this publication are derived from the following EVN project code: RP029.r e-MERLIN is a National Facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of STFC. The collaboration between LIGO/Virgo and EVN/eMERLIN is part of a project that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 653477. We thank Britt Griswold (NASA/GSFC) for graphic arts. P.G.J. acknowledges ERC-Consolidator grant No. 647208. We thank the GMRT staff for prompt scheduling of these observations. The GMRT is run by the National Center for Radio Astrophysics of the Tata Institute of Fundamental Research. INAF, Italian Institute of Astrophysics ASI, Italian Space Agency. This work is part of the research program Innovational Research Incentives Scheme (Vernieuwingsimpuls), which is financed by the Netherlands Organization for Scientific Research through the NWO VIDI grant No. 639.042.612-Nissanke and NWO TOP grant No. 62002444-Nissanke.; r r We thank ESO for granting full access to all the LVC MoU partners of the observations of GW170817 obtained with NACO and VISIR under the Observatory program 60.A-9392.
LIGO Scientific Collaboration and Virgo Collaboration, Fermi GBM, INTEGRAL, IceCube Collaboration, AstroSat Cadmium Zinc Telluride Imager Team, IPN Collaboration, The Insight-HXMT Collaboration, ANTARES Collaboration, The Swift Collaboration, AGILE Team, The 1M2H Team, The Dark Energy Camera GW-EM Collaboration and the DES Collaboration, The DLT40 Collaboration, GRAWITA: GRAvitational Wave Inaf TeAm, The Fermi Large Area Telescope Collaboration, ATCA: Australia Telescope Compact Array, ASKAP: Australian SKA Pathfinder, Las Cumbres Observatory Group, OzGrav, DWF (Deeper, Wider, Faster Program), AST3, and CAASTRO Collaborations, The VINROUGE Collaboration, MASTER Collaboration, J-GEM, GROWTH, JAGWAR, CaltechNRAO, TTU-NRAO, and NuSTAR Collaborations, Pan-STARRS, The MAXI Team, TZAC Consortium, KU Collaboration, Nordic Optical Telescope, ePESSTO, GROND, Texas Tech University, SALT Group, TOROS: Transient Robotic Observatory of the South Collaboration, The BOOTES Collaboration, MWA: Murchison Widefield Array, The CALET Collaboration, IKI-GW Follow-up Collaboration, H.E.S.S. Collaboration, LOFAR Collaboration, LWA: Long Wavelength Array, HAWC Collaboration, The Pierre Auger Collaboration, ALMA Collaboration, Euro VLBI Team, Pi of the Sky Collaboration, The Chandra Team at McGill University, DFN: Desert Fireball Network, ATLAS, High Time Resolution Universe Survey, RIMAS and RATIR, and SKA South Africa/MeerKAT ; On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of $\sim 1.7\,{\rm{s}}$ with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of ${40}_{-8}^{+8}$ Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 $\,{M}_{\odot }$. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at $\sim 40\,{\rm{Mpc}}$) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient's position $\sim 9$ and $\sim 16$ days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta. ; Kavli Foundation ; Danmarks Grundforskningsfond ; Niels Bohr International Academy ; DARK Cosmology Centre ; National Science Foundation (NSF) AST-1518052 AST-141242 AST-1411763 AST-1714498 AST-1517649 PHY-1607291 AST-1412421 AST-1313484 ; Gordon AMP; Betty Moore Foundation ; Heising-Simons Foundation ; Alfred P. 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JAXA (Japan) ; Knut & Alice Wallenberg Foundation ; Swedish Research Council ; National Space Board (Sweden) ; Istituto Nazionale Astrofisica (INAF) ; Centre National D'etudes Spatiales ; United States Department of Energy (DOE) DE-AC02-76SF00515 ; Office of Naval Research N00014-07-C0147 ; National Science Foundation under University Radio Observatory AST-1139963 AST-1139974 ; ESO Telescopes at the Paranal Observatory 099.D-0382 099.D-0622 099.D-0191 099.D-0116 ; REM telescope at the ESO La Silla Observatory 35020 ; Department of University and Research (MIUR) ; Italian Space Agency (ASI) ; Russian Academy of Sciences ; Istituto Nazionale Astrofisica (INAF) ; BIC 114332KYSB20160007 ; Chinese Academy of Sciences KJZD-EW-M06 ; National Natural Science Foundation of China 11673062 ; Oversea Talent Program of Yunnan Province ; Science & Technology Facilities Council (STFC) ; Slovenian Research Agency - Slovenia P1-0188 ; Sorbonne Paris Cite ANR-10-LABX-0023 ANR-11-IDEX-0005-02 ; GROWTH (Global Relay of Observatories Watching Transients Happen) - National Science Foundation under PIRE 1545949 ; 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We present a search for gravitational waves from 116 known millisecond and young pulsars using data from the fifth science run of the LIGO detectors. For this search, ephemerides overlapping the run period were obtained for all pulsars using radio and X-ray observations. We demonstrate an updated search method that allows for small uncertainties in the pulsar phase parameters to be included in the search. We report no signal detection from any of the targets and therefore interpret our results as upper limits on the gravitational wave signal strength. The most interesting limits are those for young pulsars. We present updated limits on gravitational radiation from the Crab pulsar, where the measured limit is now a factor of 7 below the spin-down limit. This limits the power radiated via gravitational waves to be less than similar to 2% of the available spin-down power. For the X-ray pulsar J0537-6910 we reach the spin-down limit under the assumption that any gravitational wave signal from it stays phase locked to the X-ray pulses over timing glitches, and for pulsars J1913+1011 and J1952+3252 we are only a factor of a few above the spin-down limit. Of the recycled millisecond pulsars, several of themeasured upper limits are only about an order of magnitude above their spin-down limits. For these our best (lowest) upper limit on gravitational wave amplitude is 2.3 x 10(-26) for J1603-7202 and our best (lowest) limit on the inferred pulsar ellipticity is 7.0 x 10(-8) for J2124-3358. ; Australian Research Council ; Council of Scientific and Industrial Research of India ; Istituto Nazionale di Fisica Nucleare of Italy ; Spanish Ministerio de Educacion y Ciencia ; Conselleria d'Economia Hisenda i Innovacio of the Govern de les Illes Balears ; Netherlands Organisation for Scientific Research ; Royal Society ; Scottish Funding Council ; Polish Ministry of Science and Higher Education ; Foundation for Polish Science ; Scottish Universities Physics Alliance ; National Aeronautics and Space Administration ; Carnegie Trust ; Leverhulme Trust ; David and Lucile Packard Foundation ; Research Corporation ; Alfred P. Sloan Foundation ; Natural Sciences and Engineering Research Council of Canada ; Commonwealth Government ; Astronomy
United States National Science Foundation (NSF) ; Science and Technology Facilities Council (STFC) of the United Kingdom ; Max-Planck-Society (MPS) ; State of Niedersachsen/Germany ; Australian Research Council ; International Science Linkages program of the Commonwealth of Australia ; Council of Scientific and Industrial Research of India ; Department of Science and Technology, India ; Science & Engineering Research Board (SERB), India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat and Conselleria d'Educaci, Cultura i Universitats of the Govern de les Illes Balears ; Foundation for Fundamental Research on Matter - Netherlands Organization for Scientific Research ; Polish Ministry of Science and Higher Education ; FOCUS Programme of Foundation for Polish Science ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; National Aeronautics and Space Administration ; Hungarian Scientific Research Fund (OTKA) ; Lyon Institute of Origins (LIO) ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Carnegie Trust ; Leverhulme Trust ; David and Lucile Packard Foundation ; Research Corporation ; Alfred P. Sloan Foundation ; NSF ; STFC ; MPS ; INFN ; CNRS ; Science and Technology Facilities Council ; Science and Technology Facilities Council: ST/L000938/1 ; Science and Technology Facilities Council: ST/I006285/1 ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/L000962/1 ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: ST/J00166X/1 ; Science and Technology Facilities Council: ST/L000911/1 Gravitational Waves ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: PPA/G/S/2002/00652 ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000911/1 ; Science and Technology Facilities Council: 1362895 ; Science and Technology Facilities Council: ST/I006277/1 ; Science and Technology Facilities Council: ST/H002359/1 ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/K00137X/1 ; Science and Technology Facilities Council: ST/M006735/1 ; Science and Technology Facilities Council: ST/M000931/1 ; Science and Technology Facilities Council: ST/L000938/1 Gravitational Waves ; We describe directed searches for continuous gravitational waves (GWs) in data from the sixth Laser Interferometer Gravitational-wave Observatory (LIGO) science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target ' s parameters are uncertain enough to warrant two searches, for a total of 10. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3-25.3 days using the matched-filtering. -statistic. We found no evidence of GW signals. We set 95% confidence upper limits as strong (low) as 4 x 10(-25) on intrinsic strain, 2 x 10(-7) on fiducial ellipticity, and 4 x 10(-5) on r-mode amplitude. These beat the indirect limits from energy conservation and are within the range of theoretical predictions for neutron-star ellipticities and r-mode amplitudes.
United States National Science Foundation (NSF) ; Science and Technology Facilities Council (STFC) of the United Kingdom ; Max-Planck-Society (MPS) ; State of Niedersachsen/Germany ; Italian Istituto Nazionale di Fisica Nucleare (INFN) ; French Centre National de la Recherche Scientifique (CNRS) ; Australian Research Council ; International Science Linkages program of the Commonwealth of Australia ; Council of Scientific and Industrial Research of India ; Department of Science and Technology, India ; Science & Engineering Research Board (SERB), India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat and Conselleria d'Educaci, Cultura i Universitats of the Govern de les Illes Balears ; Netherlands Organisation for Scientific Research ; National Science Centre of Poland ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; National Aeronautics and Space Administration ; Hungarian Scientific Research Fund (OTKA) ; Lyon Institute of Origins (LIO) ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; Natural Science and Engineering Research Council, Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Carnegie Trust ; Leverhulme Trust ; David and Lucile Packard Foundation ; Research Corporation ; Alfred P. Sloan Foundation ; NSF ; STFC ; MPS ; INFN ; CNRS ; Science and Technology Facilities Council ; Science and Technology Facilities Council: ST/L000938/1 Gravitational Waves ; Science and Technology Facilities Council: 1362895 ; Science and Technology Facilities Council: ST/L000962/1 ; Science and Technology Facilities Council: ST/I006285/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/L000962/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006285/1 ; Science and Technology Facilities Council: ST/I006242/1 Gravitational Waves ; Science and Technology Facilities Council: ST/J000019/1 ; Science and Technology Facilities Council: ST/N00003X/1 ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/N000064/1 ; Science and Technology Facilities Council: ST/L000954/1 Gravitational Waves ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/L000938/1 ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4 x 10(-5) and 9.4 x 10(-4) Mpc(-3) yr(-1) at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves.
Advanced LIGO ; Science and Technology Facilities Council (STFC) of the United Kingdom ; Australian Research Council ; Council of Scientific and Industrial Research of India, Department of Science and Technology, India ; Science & Engineering Research Board (SERB), India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat and Conselleria d'Educacio, Cultura i Universitats of the Govern de les Illes Balears ; National Science Centre of Poland ; FOCUS Programme of Foundation for Polish Science ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; Lyon Institute of Origins (LIO) ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Research Corporation, Ministry of Science and Technology (MOST), Taiwan ; Kavli Foundation ; Science and Technology Facilities Council ; Science and Technology Facilities Council: ST/L000954/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006242/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/J000019/1 ; Science and Technology Facilities Council: ST/N000072/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/N000633/1 ; Science and Technology Facilities Council: ST/M000931/1 ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: PPA/G/S/2002/00652 ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: ST/N00003X/1 ; We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the expected sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron-star systems, which are considered the most promising for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5 deg(2) to 20 deg(2) will require at least three detectors of sensitivity within a factor of similar to 2 of each other and with a broad frequency bandwidth. Should the third LIGO detector be relocated to India as expected, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.
Australian Research Council ; International Science Linkages program of the Commonwealth of Australia ; Council of Scientific and Industrial Research of India, Department of Science and Technology, India ; Science and Engineering Research Board, India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat ; Cultura i Universitats of the Govern de les Illes Balears ; Foundation for Fundamental Research on Matter - Netherlands Organisation for Scientific Research ; National Science Centre of Poland ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; National Aeronautics and Space Administration ; Hungarian Scientific Research Fund ; Lyon Institute of Origins ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Carnegie Trust ; Leverhulme Trust ; David and Lucile Packard Foundation ; Research Corporation ; Alfred P. Sloan Foundation ; Conselleria d'Educacio ; Science and Technology Facilities Council ; Science and Technology Facilities Council: ST/L000962/1 Gravitational Waves ; Science and Technology Facilities Council: 1362895 ; Science and Technology Facilities Council: ST/I006285/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000938/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000962/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/L000938/1 ; Science and Technology Facilities Council: ST/N000064/1 ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/L000954/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/J000019/1 ; Science and Technology Facilities Council: ST/I006242/1 Gravitational Waves ; In this paper we present the results of the first low frequency all-sky search of continuous gravitational wave signals conducted on Virgo VSR2 and VSR4 data. The search covered the full sky, a frequency range between 20 and 128 Hz with a range of spin-down between -1.0 x 10(-10) and +1.5 x 10(-11) Hz/s, and was based on a hierarchical approach. The starting point was a set of short fast Fourier transforms, of length 8192 s, built from the calibrated strain data. Aggressive data cleaning, in both the time and frequency domains, has been done in order to remove, as much as possible, the effect of disturbances of instrumental origin. On each data set a number of candidates has been selected, using the Frequency Hough transform in an incoherent step. Only coincident candidates among VSR2 and VSR4 have been examined in order to strongly reduce the false alarm probability, and the most significant candidates have been selected. The criteria we have used for candidate selection and for the coincidence step greatly reduce the harmful effect of large instrumental artifacts. Selected candidates have been subject to a follow-up by constructing a new set of longer fast Fourier transforms followed by a further incoherent analysis, still based on the Frequency Hough transform. No evidence for continuous gravitational wave signals was found, and therefore we have set a population-based joint VSR2-VSR4 90% confidence level upper limit on the dimensionless gravitational wave strain in the frequency range between 20 and 128 Hz. This is the first all-sky search for continuous gravitational waves conducted, on data of ground-based interferometric detectors, at frequencies below 50 Hz. We set upper limits in the range between about 10(-24) and 2 x 10(-23) at most frequencies. Our upper limits on signal strain show an improvement of up to a factor of similar to 2 with respect to the results of previous all-sky searches at frequencies below 80 Hz.
United States National Science Foundation (NSF) ; Science and Technology Facilities Council (STFC) of the United Kingdom ; MaxPlanck- Society (MPS) ; State of Niedersachsen/Germany ; Australian Research Council ; Netherlands Organisation for Scientific Research ; EGO consortium ; Council of Scientific and Industrial Research of India, Department of Science and Technology, India ; Science AMP; Engineering Research Board (SERB), India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat and Conselleria d'Educacio Cultura i Universitats of the Govern de les Illes Balears ; National Science Centre of Poland ; European Union ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; Lyon Institute of Origins (LIO) ; National Research Foundation of Korea, Industry Canada ; Province of Ontario through the Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Brazilian Ministry of Science, Technology, and Innovation ; Leverhulme Trust ; Research Corporation, Ministry of Science and Technology (MOST), Taiwan ; Kavli Foundation ; NSF ; STFC ; MPS ; INFN ; CNRS ; Science and Technology Facilities Council ; State of Niedersachsen/Germany: GEO600 ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/L000938/1 Gravitational Waves ; Science and Technology Facilities Council: ST/N000072/1 ; Science and Technology Facilities Council: PPA/G/S/2002/00652 ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/L000962/1 ; Science and Technology Facilities Council: ST/J00166X/1 ; Science and Technology Facilities Council: ST/M006735/1 ; Science and Technology Facilities Council: ST/I006285/1 Gravitational Waves ; Science and Technology Facilities Council: ST/J000019/1 Gravitational Waves ; Science and Technology Facilities Council: ST/I006285/1 ; Science and Technology Facilities Council: ST/J000019/1 ; Science and Technology Facilities Council: 1362895 ; Science and Technology Facilities Council: ST/M000931/1 ; Science and Technology Facilities Council: ST/L000962/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000938/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: ST/I006242/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L003465/1 ; Science and Technology Facilities Council: ST/G504284/1 ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/L000954/1 Gravitational Waves ; Science and Technology Facilities Council: ST/N00003X/1 ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: ST/N000633/1 ; Science and Technology Facilities Council: ST/L000946/1 ; The discovery of the gravitational-wave (GW) source GW150914 with the Advanced LIGO detectors provides the first observational evidence for the existence of binary black hole (BH) systems that inspiral and merge within the age of the universe. Such BH mergers have been predicted in two main types of formation models, involving isolated binaries in galactic fields or dynamical interactions in young and old dense stellar environments. The measured masses robustly demonstrate that relatively heavy BHs (greater than or similar to 25M(circle dot)) can form in nature. This discovery implies relatively weak massive-star winds and thus the formation of GW150914 in an environment with a metallicity lower than about 1/2 of the solar value. The rate of binary-BH (BBH) mergers inferred from the observation of GW150914 is consistent with the higher end of rate predictions (greater than or similar to 1 Gpc(-3) yr(-1)) from both types of formation models. The low measured redshift (z similar or equal to 0.1) of GW150914 and the low inferred metallicity of the stellar progenitor imply either BBH formation in a low-mass galaxy in the local universe and a prompt merger, or formation at high redshift with a time delay between formation and merger of several Gyr. This discovery motivates further studies of binary-BH formation astrophysics. It also has implications for future detections and studies by Advanced LIGO and Advanced Virgo, and GW detectors in space.
United States National Science Foundation (NSF) ; Science and Technology Facilities Council (STFC) of the United Kingdom ; Max-Planck Society ; State of Niedersachsen/Germany ; Australian Research Council ; Netherlands Organisation for Scientific Research ; EGO consortium ; Council of Scientific and Industrial Research of India ; Department of Science and Technology, India ; Science & Engineering Research Board (SERB), India ; Ministry of Human Resource Development, India ; Spanish Ministerio de Economia y Competitividad ; Conselleria d'Economia i Competitivitat and Conselleria d'Educacio Cultura i Universitats of the Govern de les Illes Balears ; National Science Centre of Poland ; European Commission ; Royal Society ; Scottish Funding Council ; Scottish Universities Physics Alliance ; Hungarian Scientific Research Fund (OTKA) ; Lyon Institute of Origins (LIO) ; National Research Foundation of Korea ; Industry Canada ; Province of Ontario through Ministry of Economic Development and Innovation ; National Science and Engineering Research Council Canada ; Canadian Institute for Advanced Research ; Brazilian Ministry of Science, Technology, and Innovation ; Russian Foundation for Basic Research ; Leverhulme Trust ; Research Corporation ; Ministry of Science and Technology (MOST), Taiwan ; Kavli Foundation ; Australian Government ; National Collaborative Research Infrastructure Strategy ; Government of Western Australia ; United States Department of Energy ; United States National Science Foundation ; Ministry of Science and Education of Spain ; Science and Technology Facilities Council of the United Kingdom ; Higher Education Funding Council for England ; National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign ; Kavli Institute of Cosmological Physics at the University of Chicago ; Center for Cosmology and Astro-Particle Physics at the Ohio State University ; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University ; Financiadora de Estudos e Projetos ; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; Ministerio da Ciencia, Tecnologia e Inovacao ; Deutsche Forschungsgemeinschaft ; Collaborating Institutions in the Dark Energy Survey ; National Science Foundation ; MINECO ; Centro de Excelencia Severo Ochoa ; European Research Council under European Union's Seventh Framework Programme ; ERC ; NASA (United States) ; DOE (United States) ; IN2P3/CNRS (France) ; CEA/Irfu (France) ; ASI (Italy) ; INFN (Italy) ; MEXT (Japan) ; KEK (Japan) ; JAXA (Japan) ; Wallenberg Foundation ; Swedish Research Council ; National Space Board (Sweden) ; NASA in the United States ; DRL in Germany ; INAF for the project Gravitational Wave Astronomy with the first detections of adLIGO and adVIRGO experiments ; ESA (Denmark) ; ESA (France) ; ESA (Germany) ; ESA (Italy) ; ESA (Switzerland) ; ESA (Spain) ; German INTEGRAL through DLR grant ; US under NASA Grant ; National Science Foundation PIRE program grant ; Hubble Fellowship ; KAKENHI of MEXT Japan ; JSPS ; Optical and Near-Infrared Astronomy Inter-University Cooperation Program - MEXT ; UK Science and Technology Facilities Council ; ERC Advanced Investigator Grant ; Lomonosov Moscow State University Development programm ; Moscow Union OPTICA ; Russian Science Foundation ; National Research Foundation of South Africa ; Australian Government Department of Industry and Science and Department of Education (National Collaborative Research Infrastructure Strategy: NCRIS) ; NVIDIA at Harvard University ; University of Hawaii ; National Aeronautics and Space Administration's Planetary Defense Office ; Queen's University Belfast ; National Aeronautics and Space Administration through Planetary Science Division of the NASA Science Mission Directorate ; European Research Council under European Union's Seventh Framework Programme/ERC ; STFC grants ; European Union FP7 programme through ERC ; STFC through an Ernest Rutherford Fellowship ; FONDECYT ; Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO) ; NASA in the US ; UK Space Agency in the UK ; Agenzia Spaziale Italiana (ASI) in Italy ; Ministerio de Ciencia y Tecnologia (MinCyT) ; Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CONICET) from Argentina ; USA NSF PHYS ; NSF ; ICREA ; Science and Technology Facilities Council ; UK Space Agency ; National Science Foundation: AST-1138766 ; National Science Foundation: AST-1238877 ; MINECO: AYA2012-39559 ; MINECO: ESP2013-48274 ; MINECO: FPA2013-47986 ; Centro de Excelencia Severo Ochoa: SEV-2012-0234 ; ERC: 240672 ; ERC: 291329 ; ERC: 306478 ; German INTEGRAL through DLR grant: 50 OG 1101 ; US under NASA Grant: NNX15AU74G ; National Science Foundation PIRE program grant: 1545949 ; Hubble Fellowship: HST-HF-51325.01 ; KAKENHI of MEXT Japan: 24103003 ; KAKENHI of MEXT Japan: 15H00774 ; KAKENHI of MEXT Japan: 15H00788 ; JSPS: 15H02069 ; JSPS: 15H02075 ; ERC Advanced Investigator Grant: 267697 ; Russian Science Foundation: 16-12-00085 ; Russian Science Foundation: RFBR15-02-07875 ; National Aeronautics and Space Administration's Planetary Defense Office: NNX14AM74G ; National Aeronautics and Space Administration through Planetary Science Division of the NASA Science Mission Directorate: NNX08AR22G ; European Research Council under European Union's Seventh Framework Programme/ERC: 291222 ; STFC grants: ST/I001123/1 ; STFC grants: ST/L000709/1 ; European Union FP7 programme through ERC: 320360 ; FONDECYT: 3140326 ; Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO): CE110001020 ; USA NSF PHYS: 1156600 ; NSF: 1242090 ; Science and Technology Facilities Council: Gravitational Waves ; Science and Technology Facilities Council: ST/L000946/1 ; Science and Technology Facilities Council: ST/K005014/1 ; Science and Technology Facilities Council: ST/N000668/1 ; Science and Technology Facilities Council: ST/M000966/1 ; Science and Technology Facilities Council: ST/I006269/1 ; Science and Technology Facilities Council: ST/L000709/1 ; Science and Technology Facilities Council: ST/J00166X/1 ; Science and Technology Facilities Council: ST/K000845/1 ; Science and Technology Facilities Council: ST/K00090X/1 ; Science and Technology Facilities Council: ST/N000633/1 ; Science and Technology Facilities Council: ST/H001972/1 ; Science and Technology Facilities Council: ST/L000733/1 ; Science and Technology Facilities Council: ST/N000757/1 ; Science and Technology Facilities Council: ST/M001334/1 ; Science and Technology Facilities Council: ST/J000019/1 ; Science and Technology Facilities Council: ST/M003035/1 ; Science and Technology Facilities Council: ST/I001123/1 ; Science and Technology Facilities Council: ST/N00003X/1 ; Science and Technology Facilities Council: ST/I006269/1 Gravitational Waves ; Science and Technology Facilities Council: ST/N000072/1 ; Science and Technology Facilities Council: ST/L003465/1 ; UK Space Agency: ST/P002196/1 ; This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands.
