1. A DECAM SEARCH FOR AN OPTICAL COUNTERPART TO THE LIGO GRAVITATIONAL-WAVE EVENT GW151226
- Author
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Wen-fai Fong, Brian Yanny, Shantanu Desai, John Marriner, A. K. Romer, D. L. Burke, R. C. Thomas, A. A. Plazas, A. Fausti Neto, Armin Rest, A. Carnero Rosell, D. L. Tucker, Eliot Quataert, Richard Kessler, William Wester, Kyler Kuehn, V. A. Villar, E. Suchyta, August E. Evrard, Philip S. Cowperthwaite, A. Benoit-Lévy, Keith Bechtol, K. Honscheid, Kevin Reil, M. Carrasco Kind, Robert C. Nichol, Peter K. G. Williams, Daniel Scolnic, G. Strampelli, Eric H. Neilsen, Marcos Lima, D. J. Brout, V. Scarpine, Felipe Menanteau, Edo Berger, Alex Drlica-Wagner, Derek B. Fox, Brian Nord, Gregory Tarle, Daniel Kasen, Raffaella Margutti, G. Gutierrez, Masao Sako, R. C. Smith, Carlos Cunha, I. Sevilla-Noarbe, Huan Lin, Juan Garcia-Bellido, Ryan Chornock, Ben Farr, David J. James, Ramon Miquel, Brian D. Metzger, Pablo Fosalba, Robert Armstrong, L. N. da Costa, Duncan A. Brown, Alistair R. Walker, S. Allam, Robert A. Gruendl, Hsin-Yu Chen, Maria R. Drout, Marcelle Soares-Santos, J. Annis, Zoheyr Doctor, Flavia Sobreira, Thomas Matheson, M. W. G. Johnson, Jennifer L. Marshall, S. B. Cenko, F. B. Abdalla, Elisabeth Krause, Joseph J. Mohr, Joshua A. Frieman, Tommaso Giannantonio, H. T. Diehl, M. S. S. Gill, Daniel Thomas, E. Buckley-Geer, David Brooks, Francisco J. Castander, E. Bertin, Marcio A. G. Maia, Michael D. Johnson, Ken Herner, Nathan Smith, Daniel Gruen, D. A. Finley, J. Carretero, D. W. Gerdes, Daniel A. Goldstein, J. P. Dietrich, Jochen Weller, T. M. C. Abbott, R. J. Foley, E. J. Sanchez, C. B. D'Andrea, Nikolay Kuropatkin, Daniel E. Holz, Ricardo L. C. Ogando, UAM. Departamento de Física Teórica, Harvard Smithsonian Ctr Astrophys, Fermilab Natl Accelerator Lab, Univ Penn, Syracuse Univ, NASA, Univ Maryland, Univ Chicago, Ohio Univ, Univ Calif Santa Cruz, Univ Illinois, Univ Arizona, Penn State Univ, Univ Autonoma Madrid, Stanford Univ, SLAC Natl Accelerator Lab, Natl Ctr Supercomputing Applicat, Univ Calif Berkeley, Lawrence Berkeley Natl Lab, NYU, Natl Opt Astron Observ, Columbia Univ, Space Telescope Sci Inst, Universidade Estadual Paulista (Unesp), Lab Interinst E Astron LIneA, UCL, Rhodes Univ, Princeton Univ, Univ Wisconsin, CNRS, Univ Paris 06, Observ Nacl, IEEC CSIC, Barcelona Inst Sci & Technol, Univ Portsmouth, Univ Southampton, Univ Munich, Excellence Cluster Universe, Univ Michigan, Univ Cambridge, Ohio State Univ, Australian Astron Observ, Universidade de São Paulo (USP), Texas A&M Univ, Inst Catalana Recerca & Estudis Avancats, Max Planck Inst Extraterr Phys, CALTECH, Univ Sussex, and Ctr Invest Energet Medioambientales & Tecnol CIEM
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,close [binaries] ,FOS: Physical sciences ,Astrophysics ,Surveys ,Kilonova ,Astronomy & Astrophysics ,01 natural sciences ,Gravitational waves ,neutron [stars] ,surveys ,Stars: Neutron ,0103 physical sciences ,GW151226 ,010303 astronomy & astrophysics ,STFC ,QB ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,astro-ph.HE ,010308 nuclear & particles physics ,Gravitational wave ,Detector ,Física ,RCUK ,Astronomy and Astrophysics ,Galaxy ,LIGO ,Binaries: Close ,Supernova ,gravitational waves ,13. Climate action ,Space and Planetary Science ,Dark energy ,astro-ph.CO ,Catalogs ,Astrophysics - High Energy Astrophysical Phenomena ,catalogs ,Astronomical and Space Sciences ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Astrophysical Journal Letters 826.2 (2016): L29 reproduced by permission of the AAS, We report the results of a Dark Energy Camera optical follow-up of the gravitational-wave (GW) event GW151226, discovered by the Advanced Laser Interferometer Gravitational-wave Observatory detectors. Our observations cover 28.8 deg2 of the localization region in the i and z bands (containing 3% of the BAYESTAR localization probability), starting 10 hr after the event was announced and spanning four epochs at 2-24 days after the GW detection. We achieve 5σ point-source limiting magnitudes of i ≈ 21.7 and z ≈ 21.5, with a scatter of 0.4 mag, in our difference images. Given the two-day delay, we search this area for a rapidly declining optical counterpart with ≥ 3σ significance steady decline between the first and final observations. We recover four sources that pass our selection criteria, of which three are cataloged active galactic nuclei. The fourth source is offset by 5.8 arcsec from the center of a galaxy at a distance of 187 Mpc, exhibits a rapid decline by 0.5 mag over 4 days, and has a red color of i - z ≈ 0.3 mag. These properties could satisfy a set of cuts designed to identify kilonovae. However, this source was detected several times, starting 94 days prior to GW151226, in the Pan-STARRS Survey for Transients (dubbed as PS15cdi) and is therefore unrelated to the GW event. Given its long-term behavior, PS15cdi is likely a Type IIP supernova that transitioned out of its plateau phase during our observations, mimicking a kilonova-like behavior. We comment on the implications of this detection for contamination in future optical follow-up observations, P.S.C. is grateful for support provided by the NSF through the Graduate Research Fellowship Program, grant DGE1144152. R. J.F. gratefully acknowledges support from NSF grant AST– 1518052 and the Alfred P. Sloan Foundation. D.E.H. was supported by NSF CAREER grant PHY-1151836. He also acknowledges support from the Kavli Institute for Cosmological Physics at the University of Chicago through NSF grant PHY- 1125897 as well as an endowment from the Kavli Foundation. The DES Data Management System is supported by the NSF under grant number AST-1138766. The DES participants from Spanish institutions are partially supported by MINECO under grants AYA2012-39559, ESP2013-48274, FPA2013-47986, and Centro de Excelencia Severo Ochoa SEV-2012-0234. Research leading to these results has received funding from the ERC under the EU’s 7th Framework Programme including grants ERC 240672, 291329,and 306478
- Published
- 2016