N. M. Amin⁴³, K. Andeen⁴¹, C. Arguelles¹³, Y. Ashida⁵², S. Athanasiadou⁶³, S. N. Axani⁴³, R. Babu²³, X. Bai⁴⁹, J. Baines-Holmes³⁹, A. Balagopal V.^43,39, S. W. Barwick²⁹, S. Bash²⁶, V. Basu⁵², R. Bay⁶, J. J. Beatty^20,19, J. Becker Tjus^9,‡, P. Behrens¹, J. Beise⁶¹, C. Bellenghi²⁶, B. Benkel⁶³, S. BenZvi⁵¹, D. Berley¹⁸, E. Bernardini^47,§, D. Z. Besson³⁵, E. Blaufuss¹⁸, L. Bloom⁵⁸, S. Blot⁶³, I. Bodo³⁹, F. Bontempo³⁰, J. Y. Book Motzkin¹³, C. Boscolo Meneguolo^47,§, S. Boser⁴⁰, O. Botner⁶¹, J. Bottcher¹, J. Braun³⁹, B. Brinson⁴, Z. Brisson-Tsavoussis³², R. T. Burley², D. Butterfield³⁹, M. A. Campana⁴⁸, K. Carloni¹³, J. Carpio^34,33, S. Chattopadhyay^39,†, N. Chau¹⁰, Z. Chen⁵⁵, D. Chirkin³⁹, S. Choi⁵², B. A. Clark¹⁸, A. Coleman⁶¹, P. Coleman¹, G. H. Collin¹⁴, D. A. Coloma Borja⁴⁷, A. Connolly^20,19, J. M. Conrad¹⁴, R. Corley⁵², D. F. Cowen^59,60, C. De Clercq¹¹, J. J. DeLaunay⁵⁹, D. Delgado¹³, T. Delmeulle¹⁰, S. Deng¹, P. Desiati³⁹, K. D. de Vries¹¹, G. de Wasseige³⁶, T. DeYoung²³, J. C. Diaz-Velez³⁹, S. DiKerby²³, M. Dittmer⁴², A. Domi²⁵, L. Draper⁵², L. Dueser¹, D. Durnford²⁴, K. Dutta⁴⁰, M. A. DuVernois³⁹, T. Ehrhardt⁴⁰, L. Eidenschink²⁶, A. Eimer²⁵, P. Eller²⁶, E. Ellinger⁶², D. Elsasser²², R. Engel^30,31, H. Erpenbeck³⁹, W. Esmail⁴², S. Eulig¹³, J. Evans¹⁸, P. A. Evenson⁴³, K. L. Fan¹⁸, K. Fang³⁹, K. Farrag¹⁵, A. R. Fazely⁵, A. Fedynitch⁵⁷, N. Feigl⁸, C. Finley⁵⁴, L. Fischer⁶³, D. Fox⁵⁹, A. Franckowiak⁹, S. Fukami⁶³, P. Furst¹, J. Gallagher³⁸, E. Ganster¹, A. Garcia¹³, M. Garcia⁴³, G. Garg^39,†, E. Genton^13,36, L. Gerhardt⁷, A. Ghadimi⁵⁸, C. Glaser⁶¹, T. Glusenkamp⁶¹, J. G. Gonzalez⁴³, S. Goswami^34,33, A. Granados²³, D. Grant¹², S. J. Gray¹⁸, S. Griffin³⁹, S. Griswold⁵¹, K. M. Groth²¹, D. Guevel³⁹, C. Gunther¹, P. Gutjahr²², C. Ha⁵³, C. Haack²⁵, A. Hallgren⁶¹, L. Halve¹, F. Halzen³⁹, L. Hamacher¹, M. Ha Minh²⁶, M. Handt¹, K. Hanson³⁹, J. Hardin¹⁴, A. A. Harnisch²³, P. Hatch³², A. Haungs³⁰, J. Haussler¹, K. Helbing⁶², J. Hellrung⁹, B. Henke²³, L. Hennig²⁵, F. Henningsen¹², L. Heuermann¹, R. Hewett¹⁷, N. Heyer⁶¹, S. Hickford⁶², A. Hidvegi⁵⁴, C. Hill¹⁵, G. C. Hill², R. Hmaid¹⁵, K. D. Hoffman¹⁸, D. Hooper³⁹, S. Hori³⁹, K. Hoshina^39,∥, M. Hostert¹³, W. Hou³⁰, T. Huber³⁰, K. Hultqvist⁵⁴, K. Hymon^22,57, A. Ishihara¹⁵, W. Iwakiri¹⁵, M. Jacquart²¹, S. Jain³⁹, O. Janik²⁵, M. Jansson³⁶, M. Jeong⁵², M. Jin¹³, N. Kamp¹³, D. Kang³⁰, W. Kang⁴⁸, X. Kang⁴⁸, A. Kappes⁴², L. Kardum²², T. Karg⁶³, M. Karl²⁶, A. Karle³⁹, A. Katil²⁴, M. Kauer³⁹, J. L. Kelley³⁹, M. Khanal⁵², A. Khatee Zathul³⁹, A. Kheirandish^34,33, H. Kimku⁵³, J. Kiryluk⁵⁵, C. Klein²⁵, S. R. Klein^7,6, Y. Kobayashi¹⁵, A. Kochocki²³, R. Koirala⁴³, H. Kolanoski⁸, T. Kontrimas²⁶, L. Kopke⁴⁰, C. Kopper²⁵, D. J. Koskinen²¹, P. Koundal⁴³, M. Kowalski^8,63, T. Kozynets²¹, N. Krieger⁹, J. Krishnamoorthi^39,†, T. Krishnan¹³, K. Kruiswijk³⁶, E. Krupczak²³, A. Kumar⁶³, E. Kun⁹, N. Kurahashi⁴⁸, N. Lad⁶³, C. Lagunas Gualda²⁶, L. Lallement Arnaud¹⁰, M. Lamoureux³⁶, M. J. Larson¹⁸, F. Lauber⁶², J. P. Lazar³⁶, K. Leonard DeHolton⁶⁰, A. Leszczynska⁴³, J. Liao⁴, C. Lin⁴³, Y. T. Liu⁶⁰, M. Liubarska²⁴, C. Love⁴⁸, L. Lu³⁹, F. Lucarelli²⁷, W. Luszczak^20,19, Y. Lyu^6,7, J. Madsen³⁹, E. Magnus¹¹, Y. Makino³⁹, E. Manao²⁶, S. Mancina^47,¶, A. Mand³⁹, I. C. Maris¹⁰, S. Marka⁴⁵, Z. Marka⁴⁵, L. Marten¹, I. Martinez-Soler¹³, R. Maruyama⁴⁴, J. Mauro³⁶, F. Mayhew²³, F. McNally³⁷, J. V. Mead²¹, K. Meagher³⁹, S. Mechbal⁶³, A. Medina²⁰, M. Meier¹⁵, Y. Merckx¹¹, L. Merten⁹, J. Mitchell⁵, L. Molchany⁴⁹, T. Montaruli²⁷, R. W. Moore²⁴, Y. Morii¹⁵, A. Mosbrugger²⁵, M. Moulai³⁹, D. Mousadi⁶³, E. Moyaux³⁶, T. Mukherjee³⁰, R. Naab⁶³, M. Nakos³⁹, U. Naumann⁶², J. Necker⁶³, L. Neste⁵⁴, M. Neumann⁴², H. Niederhausen²³, M. U. Nisa²³, K. Noda¹⁵, A. Noell¹, A. Novikov⁴³, A. Obertacke Pollmann¹⁵, V. O’Dell³⁹, A. Olivas¹⁸, R. Orsoe²⁶, J. Osborn³⁹, E. O’Sullivan⁶¹, V. Palusova⁴⁰, H. Pandya⁴³, A. Parenti¹⁰, N. Park³², V. Parrish²³, E. N. Paudel⁵⁸, L. Paul⁴⁹, C. Perez de los Heros⁶¹, T. Pernice⁶³, J. Peterson³⁹, M. Plum⁴⁹, A. Ponten⁶¹, V. Poojyam⁵⁸, Y. Popovych⁴⁰, M. Prado Rodriguez³⁹, B. Pries²³, R. Procter-Murphy¹⁸, G. T. Przybylski⁷, L. Pyras⁵², C. Raab³⁶, J. Rack-Helleis⁴⁰, N. Rad⁶³, M. Ravn⁶¹, K. Rawlins³, Z. Rechav³⁹, A. Rehman⁴³, I. Reistroffer⁴⁹, E. Resconi²⁶, S. Reusch⁶³, C. D. Rho⁵⁶, W. Rhode²², L. Ricca³⁶, B. Riedel³⁹, A. Rifaie⁶², E. J. Roberts², S. Robertson^6,7, M. Rongen²⁵, A. Rosted¹⁵, C. Rott⁵², T. Ruhe²², L. Ruohan²⁶, D. Ryckbosch²⁸, J. Saffer³¹, D. Salazar-Gallegos²³, P. Sampathkumar³⁰, A. Sandrock⁶², G. Sanger-Johnson²³, M. Santander⁵⁸, S. Sarkar⁴⁶, J. Savelberg¹, M. Scarnera³⁶, P. Schaile²⁶, M. Schaufel¹, H. Schieler³⁰, S. Schindler²⁵, L. Schlickmann⁴⁰, B. Schluter⁴², F. Schluter¹⁰, N. Schmeisser⁶², T. Schmidt¹⁸, F. G. Schroder^43,30, L. Schumacher²⁵, S. Schwirn¹, S. Sclafani¹⁸, D. Seckel⁴³, L. Seen³⁹, M. Seikh³⁵, S. Seunarine⁵⁰, P. A. Sevle Myhr³⁶, R. Shah⁴⁸, S. Shefali³¹, N. Shimizu¹⁵, B. Skrzypek⁶, R. Snihur³⁹, J. Soedingrekso²², A. Sogaard²¹, D. Soldin⁵², P. Soldin¹, G. Sommani⁹, C. Spannfellner²⁶, G. M. Spiczak⁵⁰, C. Spiering⁶³, J. Stachurska²⁸, M. Stamatikos²⁰, T. Stanev⁴³, T. Stezelberger⁷, T. Sturwald⁶², T. Stuttard²¹, G. W. Sullivan¹⁸, I. Taboada⁴, S. Ter-Antonyan⁵, A. Terliuk²⁶, A. Thakuri⁴⁹, M. Thiesmeyer³⁹, W. G. Thompson¹³, J. Thwaites³⁹, S. Tilav⁴³, K. Tollefson²³, S. Toscano¹⁰, D. Tosi³⁹, A. Trettin⁶³, A. K. Upadhyay^39,†, K. Upshaw⁵, A. Vaidyanathan⁴¹, N. Valtonen-Mattila^9,61, J. Valverde⁴¹, J. Vandenbroucke³⁹, T. Van Eeden⁶³, N. van Eijndhoven¹¹, L. Van Rootselaar²², J. van Santen⁶³, J. Vara⁴², F. Varsi³¹, M. Venugopal³⁰, M. Vereecken³⁶, S. Vergara Carrasco¹⁷, S. Verpoest⁴³, D. Veske⁴⁵, A. Vijai¹⁸, J. Villarreal¹⁴, C. Walck⁵⁴, A. Wang⁴, E. H. S. Warrick⁵⁸, C. Weaver²³, P. Weigel¹⁴, A. Weindl³⁰, J. Weldert⁴⁰, A. Y. Wen¹³, C. Wendt³⁹, J. Werthebach²², M. Weyrauch³⁰, N. Whitehorn²³, C. H. Wiebusch¹, D. R. Williams⁵⁸, L. Witthaus²², M. Wolf²⁶, G. Wrede²⁵, X. W. Xu⁵, J. P. Yanez²⁴, Y. Yao³⁹, E. Yildizci³⁹, S. Yoshida¹⁵, R. Young³⁵, F. Yu¹³, S. Yu⁵², T. Yuan³⁹, A. Zegarelli⁹, S. Zhang²³, Z. Zhang⁵⁵, P. Zhelnin¹³, and P. Zilberman³⁹ (IceCube Collaboration)

• ¹III. Physikalisches Institut, RWTH Aachen University, D-52056 Aachen, Germany
• ²Department of Physics, University of Adelaide, Adelaide, 5005, Australia
• ³Department of Physics and Astronomy, University of Alaska Anchorage, 3211 Providence Dr., Anchorage, Alaska 99508, USA
• ⁴School of Physics and Center for Relativistic Astrophysics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
• ⁵Department of Physics, Southern University, Baton Rouge, Louisiana 70813, USA
• ⁶Department of Physics, University of California, Berkeley, California 94720, USA
• ⁷Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
• ⁸Institut für Physik, Humboldt-Universität zu Berlin, D-12489 Berlin, Germany
• ⁹Fakultät für Physik and Astronomie, Ruhr-Universität Bochum, D-44780 Bochum, Germany
• ¹⁰Université Libre de Bruxelles, Science Faculty CP230, B-1050 Brussels, Belgium
• ¹¹Vrije Universiteit Brussel (VUB), Dienst ELEM, B-1050 Brussels, Belgium
• ¹²Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
• ¹³Department of Physics and Laboratory for Particle Physics and Cosmology, Harvard University, Cambridge, Massachusetts 02138, USA
• ¹⁴Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
• ¹⁵Department of Physics and The International Center for Hadron Astrophysics, Chiba University, Chiba 263-8522, Japan
• ¹⁶Department of Physics, Loyola University Chicago, Chicago, Illinois 60660, USA
• ¹⁷Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
• ¹⁸Department of Physics, University of Maryland, College Park, Maryland 20742, USA
• ¹⁹Department of Astronomy, Ohio State University, Columbus, Ohio 43210, USA
• ²⁰Department of Physics and Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210, USA
• ²¹Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
• ²²Department of Physics, TU Dortmund University, D-44221 Dortmund, Germany
• ²³Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
• ²⁴Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada
• ²⁵Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
• ²⁶Physik-department, Technische Universität München, D-85748 Garching, Germany
• ²⁷Département de physique nucléaire et corpusculaire, Université de Genève, CH-1211 Genève, Switzerland
• ²⁸Department of Physics and Astronomy, University of Gent, B-9000 Gent, Belgium
• ²⁹Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
• ³⁰Karlsruhe Institute of Technology, Institute for Astroparticle Physics, D-76021 Karlsruhe, Germany
• ³¹Karlsruhe Institute of Technology, Institute of Experimental Particle Physics, D-76021 Karlsruhe, Germany
• ³²Department of Physics, Engineering Physics, and Astronomy, Queen’s University, Kingston, Ontario K7L 3N6, Canada
• ³³Department of Physics and Astronomy, University of Nevada, Las Vegas, Nevada 89154, USA
• ³⁴Nevada Center for Astrophysics, University of Nevada, Las Vegas, Nevada 89154, USA
• ³⁵Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, USA
• ³⁶Centre for Cosmology, Particle Physics and Phenomenology - CP3, Université catholique de Louvain, Louvain-la-Neuve, Belgium
• ³⁷Department of Physics, Mercer University, Macon, Georgia 31207-0001, USA
• ³⁸Department of Astronomy, University of Wisconsin—Madison, Madison, Wisconsin 53706, USA
• ³⁹Department of Physics and Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin—Madison, Madison, Wisconsin 53706, USA
• ⁴⁰Institute of Physics, University of Mainz, Staudinger Weg 7, D-55099 Mainz, Germany
• ⁴¹Department of Physics, Marquette University, Milwaukee, Wisconsin 53201, USA
• ⁴²Institut für Kernphysik, Universität Münster, D-48149 Münster, Germany
• ⁴³Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
• ⁴⁴Department of Physics, Yale University, New Haven, Connecticut 06520, USA
• ⁴⁵Columbia Astrophysics and Nevis Laboratories, Columbia University, New York, New York 10027, USA
• ⁴⁶Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
• ⁴⁷Dipartimento di Fisica e Astronomia Galileo Galilei, Università Degli Studi di Padova, I-35122 Padova PD, Italy
• ⁴⁸Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, USA
• ⁴⁹Physics Department, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
• ⁵⁰Department, of Physics, University of Wisconsin, River Falls, Wisconsin 54022, USA
• ⁵¹Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
• ⁵²Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA
• ⁵³Department of Physics, Chung-Ang University, Seoul 06974, Republic of Korea
• ⁵⁴Oskar Klein Centre and Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
• ⁵⁵Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
• ⁵⁶Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
• ⁵⁷Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan
• ⁵⁸Department of Physics and Astronomy, University of Alabama, Tuscaloosa, Alabama 35487, USA
• ⁵⁹Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
• ⁶⁰Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
• ⁶¹Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala, Sweden
• ⁶²Department of Physics, University of Wuppertal, D-42119 Wuppertal, Germany
• ⁶³Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, D-15738 Zeuthen, Germany

• ^*Full author list given at the end of the Letter.
• ^†Also at Institute of Physics, Sachivalaya Marg, Sainik School Post, Bhubaneswar 751005, India.
• ^‡Also at Department of Space, Earth and Environment, Chalmers University of Technology, 412 96 Gothenburg, Sweden.
• ^§Also at INFN Padova, I-35131 Padova, Italy.
• ^∥Also at Earthquake Research Institute, University of Tokyo, Bunkyo, Tokyo 113-0032, Japan.
• ^¶Present address: INFN Padova, I-35131 Padova, Italy.