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GROWTH on S190510g: DECam Observation Planning and Follow-Up of a Distant Binary Neutron Star Merger Candidate

Andreoni, Igor and Goldstein, Daniel A. and Anand, Shreya and Coughlin, Michael W. and Singer, Leo P. and Ahumada, Tomás and Medford, Michael and Kool, Erik C. and Webb, Sara and Bulla, Mattia and Bloom, Joshua S. and Kasliwal, Mansi M. and Nugent, Peter E. and Bagdasaryan, Ashot and Barnes, Jennifer and Cook, David O. and Cooke, Jeff and Duev, Dmitry A. and Fremling, U. Christoffer and Gatkine, Pradip and Golkhou, V. Zach and Kong, Albert K. H. and Mahabal, Ashish and Martínez-Palomera, Jorge and Tao, Duo and Zhang, Keming (2019) GROWTH on S190510g: DECam Observation Planning and Follow-Up of a Distant Binary Neutron Star Merger Candidate. Astrophysical Journal Letters, 881 (1). Art. No. L16. ISSN 2041-8213.

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The first two months of the third Advanced LIGO and Virgo observing run (2019 April–May) showed that distant gravitational-wave (GW) events can now be readily detected. Three candidate mergers containing neutron stars (NS) were reported in a span of 15 days, all likely located more than 100 Mpc away. However, distant events such as the three new NS mergers are likely to be coarsely localized, which highlights the importance of facilities and scheduling systems that enable deep observations over hundreds to thousands of square degrees to detect the electromagnetic counterparts. On 2019 May 10 02:59:39.292 UT the GW candidate S190510g was discovered and initially classified as a binary neutron star (BNS) merger with 98% probability. The GW event was localized within an area of 3462 deg^2, later refined to 1166 deg^2 (90%) at a distance of 227 ± 92 Mpc. We triggered Target-of-Opportunity observations with the Dark Energy Camera (DECam), a wide-field optical imager mounted at the prime focus of the 4 m Blanco Telescope at Cerro Tololo Inter-American Observatory in Chile. This Letter describes our DECam observations and our real-time analysis results, focusing in particular on the design and implementation of the observing strategy. Within 24 hr of the merger time, we observed 65% of the total enclosed probability of the final skymap with an observing efficiency of 94%. We identified and publicly announced 13 candidate counterparts. S190510g was reclassified 1.7 days after the merger, after our observations were completed, with a "BNS merger" probability reduced from 98% to 42% in favor of a "terrestrial classification.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Andreoni, Igor0000-0002-8977-1498
Goldstein, Daniel A.0000-0003-3461-8661
Coughlin, Michael W.0000-0002-8262-2924
Singer, Leo P.0000-0001-9898-5597
Ahumada, Tomás0000-0002-2184-6430
Medford, Michael0000-0002-7226-0659
Kool, Erik C.0000-0002-7252-3877
Webb, Sara0000-0003-2601-1472
Bulla, Mattia0000-0002-8255-5127
Bloom, Joshua S.0000-0002-7777-216X
Kasliwal, Mansi M.0000-0002-5619-4938
Nugent, Peter E.0000-0002-3389-0586
Barnes, Jennifer0000-0003-3340-4784
Cook, David O.0000-0002-6877-7655
Cooke, Jeff0000-0001-5703-2108
Duev, Dmitry A.0000-0001-5060-8733
Fremling, U. Christoffer0000-0002-4223-103X
Gatkine, Pradip0000-0002-1955-2230
Golkhou, V. Zach0000-0001-8205-2506
Kong, Albert K. H.0000-0002-5105-344X
Mahabal, Ashish0000-0003-2242-0244
Martínez-Palomera, Jorge0000-0002-7395-4935
Zhang, Keming0000-0002-9870-5695
Additional Information:© 2019 The American Astronomical Society. Received 2019 May 31; revised 2019 July 15; accepted 2019 July 18; published 2019 August 9. On behalf of the entire GROWTH team, I.A. and D.A.G. gratefully acknowledge Steve Heathcote, Kathy Vivas, Tim Abbott, and the staff at CTIO and NOAO for facilitating these target-of-opportunity observations. I.A. and M.M.K. thank Myungshin Im and the KMTNet team for coordinating follow-up observations of DECam-GROWTH candidates. The authors thank the anonymous referee for a useful review of the manuscript. 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), University of Washington (USA), Los Alamos National Laboratory (USA), Tokyo Institute of Technology (Japan), National Central University (Taiwan), Indian Institute of Astrophysics (India), Indian Institute of Technology Bombay (India), Weizmann Institute of Science (Israel), The Oskar Klein Centre at Stockholm University (Sweden), Humboldt University (Germany), Liverpool John Moores University (UK), and University of Sydney (Australia). D.A.G. acknowledges support from Hubble Fellowship grant HST-HF2-51408.001-A. S.A. acknowledges support from the PMA Division Medberry Fellowship at the California Institute of Technology. Support for Program number HST-HF2-51408.001-A is provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. M.W.C. is supported by the David and Ellen Lee Postdoctoral Fellowship at the California Institute of Technology. M.B. and E.K. acknowledge support from the G.R.E.A.T. research environment funded by the Swedish National Science Foundation. P.N. acknowledges support from the DOE through DE-FOA-0001088, Analytical Modeling for Extreme-Scale Computing Environments. J.S.B., J.M.-P., and K.Z. are partially supported by a Gordon and Betty Moore Foundation Data-Driven Discovery grant. Support for J.B. was provided in part by the National Aeronautics and Space Administration(NASA)through the Einstein Fellowship Program, grant No. PF7-180162. P.G. is supported by NASA Earth and Space Science Fellowship (ASTRO18F-0085). A.A.M. acknowledges support from the following grants: NSF AST-1749235, NSF-1640818 and NASA 16-ADAP16-0232. V.Z.G. acknowledges support from the University of Washington College of Arts and Sciences, Department of Astronomy, and the DIRAC Institute. University of Washington's DIRAC Institute is supported through generous gifts from the Charles and Lisa Simonyi Fund for Arts and Sciences, and the Washington Research Foundation. A.K.H.K. acknowledges support from the Ministry of Science and Technology of the Republic of China (Taiwan) under grants 106-2628-M-007-005 and 107-2628-M-007-003. This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) collaborating institutions: Argonne National Lab, University of California Santa Cruz, University of Cambridge, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid, University of Chicago, University College London, DES-Brazil consortium, University of Edinburgh, ETH-Zurich, University of Illinois at Urbana-Champaign, Institut de Ciencies de l'Espai, Institut de Fisica d'Altes Energies, Lawrence Berkeley National Lab, Ludwig-Maximilians Universitat, University of Michigan, National Optical Astronomy Observatory, University of Nottingham, Ohio State University, University of Pennsylvania, University of Portsmouth, SLAC National Lab, Stanford University, University of Sussex, and Texas A&M University. Funding for DES, including DECam, has been provided by the U.S. Department of Energy, National Science Foundation, Ministry of Education and Science (Spain), Science and Technology Facilities Council (UK), Higher Education Funding Council (England), National Center for Supercomputing Applications, Kavli Institute for Cosmological Physics, Financiadora de Estudos e Projetos, Fundação Carlos Chagas Filho de Amparo a Pesquisa, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência e Tecnologia (Brazil), the German Research Foundation-sponsored cluster of excellence "Origin and Structure of the Universe" and the DES collaborating institutions. This work has made use of data from the European Space Agency (ESA) mission Gaia (Gaia Collaboration et al. 2016, 2018) (, processed by the Gaia Data Processing and Analysis Consortium (DPAC, Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.
Group:Infrared Processing and Analysis Center (IPAC), Astronomy Department
Funding AgencyGrant Number
NASA Hubble FellowshipHST-HF2-51408.001-A
Caltech Division of Physics, Mathematics and AstronomyUNSPECIFIED
David and Ellen Lee Postdoctoral ScholarshipUNSPECIFIED
Swedish Research CouncilUNSPECIFIED
Department of Energy (DOE)DE-FOA-0001088
Gordon and Betty Moore FoundationUNSPECIFIED
NASA Einstein FellowshipPF7-180162
NASA Earth and Space Science FellowshipASTRO18F-0085
University of WashingtonUNSPECIFIED
Charles and Lisa Simonyi Fund for Arts and SciencesUNSPECIFIED
Washington Research FoundationUNSPECIFIED
Ministry of Science and Technology (Taipei)106-2628-M-007-005
Ministry of Science and Technology (Taipei)107-2628-M-007-003
Ministerio de Educación y Ciencia (MEC)UNSPECIFIED
Science and Technology Facilities Council (STFC)UNSPECIFIED
Higher Education Funding Council for EnglandUNSPECIFIED
National Center for Supercomputing ApplicationsUNSPECIFIED
Kavli Institute for Cosmological PhysicsUNSPECIFIED
Financiadora de Estudos e Projetos (FINEP)UNSPECIFIED
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ)UNSPECIFIED
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)UNSPECIFIED
Ministerio da Ciencia e Tecnologia (MCT)UNSPECIFIED
Deutsche Forschungsgemeinschaft (DFG)UNSPECIFIED
Argonne National LaboratoryUNSPECIFIED
University of California, Santa CruzUNSPECIFIED
University of CambridgeUNSPECIFIED
Centro de Investigaciones Energeticas, Medioambientales y TecnologicasUNSPECIFIED
University of ChicagoUNSPECIFIED
University College LondonUNSPECIFIED
DES-Brazil consortiumUNSPECIFIED
University of EdinburghUNSPECIFIED
University of Illinois Urbana-ChampaignUNSPECIFIED
Institut de Ciencies de l'EspaiUNSPECIFIED
Institut de Fisica d'Altes EnergiesUNSPECIFIED
Lawrence Berkeley National LaboratoryUNSPECIFIED
Ludwig-Maximilians UniversitatUNSPECIFIED
University of MichiganUNSPECIFIED
National Optical Astronomy Observatory (NOAO)UNSPECIFIED
University of NottinghamUNSPECIFIED
Ohio State UniversityUNSPECIFIED
University of PennsylvaniaUNSPECIFIED
University of PortsmouthUNSPECIFIED
Stanford Linear Accelerator CenterUNSPECIFIED
Stanford UniversityUNSPECIFIED
University of SussexUNSPECIFIED
Texas A&M UniversityUNSPECIFIED
Gaia Multilateral AgreementUNSPECIFIED
Subject Keywords:binaries: general – gravitational waves – methods: observational – stars: neutron – supernovae: general
Issue or Number:1
Record Number:CaltechAUTHORS:20190619-081420386
Persistent URL:
Official Citation:Igor Andreoni et al 2019 ApJL 881 L16
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:96513
Deposited By: Tony Diaz
Deposited On:19 Jun 2019 17:25
Last Modified:03 Oct 2019 21:22

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