Observation of anisotropy in the arrival directions of galactic cosmic rays at multiple angular scales with IceCube
Between 2009 May and 2010 May, the IceCube neutrino detector at the South Pole recorded 32 billion muons generated in air showers produced by cosmic rays with a median energy of 20 TeV. With a data set of this size, it is possible to probe the southern sky for per-mil anisotropy on all angular scale...
Published in: | The Astrophysical Journal |
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Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2011
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Online Access: | https://biblio.ugent.be/publication/2146317 http://hdl.handle.net/1854/LU-2146317 https://doi.org/10.1088/0004-637X/740/1/16 https://biblio.ugent.be/publication/2146317/file/2946458 |
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ftunivgent:oai:archive.ugent.be:2146317 |
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openpolar |
institution |
Open Polar |
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Ghent University Academic Bibliography |
op_collection_id |
ftunivgent |
language |
English |
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Physics and Astronomy astroparticle physics cosmic rays MILAGRO HOT-SPOTS AIR-SHOWER ARRAY ENERGY-SPECTRUM INTENSITY TELESCOPE ASTRONOMY |
spellingShingle |
Physics and Astronomy astroparticle physics cosmic rays MILAGRO HOT-SPOTS AIR-SHOWER ARRAY ENERGY-SPECTRUM INTENSITY TELESCOPE ASTRONOMY Abbasi, R Abdou, Yasser Abu-Zayyad, T Adams, J Aguilar, JA Ahlers, M Altmann, D Andeen, K Auffenberg, J Bai, X Baker, M Barwick, SW Bay, R Alba, JLB Beattie, K Beatty, JJ Bechet, S Becker, JK Becker, KH Benabderrahmane, ML BenZvi, S Berdermann, J Berghaus, P Berley, D Bernardini, E Bertrand, D Besson, DZ Bindig, D Bissok, M Blaufuss, E Blumenthal, J Boersma, DJ Bohm, C Bose, D Boser, S Botner, O Brown, AM Buitink, S Caballero-Mora, KS Carson, Michael Chirkin, D Christy, B Clem, J Clevermann, F Cohen, S Colnard, C Cowen, DF D'Agostino, MV Danninger, M Daughhetee, J Davis, JC De Clercq, C Demirors, L Denger, T Depaepe, O Descamps, Freija Desiati, P De Vries-Uiterweerd, Garmt DeYoung, T Diaz-Velez, JC Dierckxsens, M Dreyer, J Dumm, JP Ehrlich, R Eisch, J Ellsworth, RW Engdegard, O Euler, S Evenson, PA Fadiran, O Fazely, AR Fedynitch, A Feintzeig, J Feusels, Tom Filimonov, K Finley, C Fischer-Wasels, T Foerster, MM Fox, BD Franckowiak, A Franke, R Gaisser, TK Gallagher, J Gerhardt, L Gladstone, L Glusenkamp, T Goldschmidt, A Goodman, JA Gora, D Grant, D Griesel, T Gross, A Grullon, S Gurtner, M Ha, C Haj Ismail, Abd Al Karim Hallgren, A Halzen, F Han, K Hanson, K Heinen, D Helbing, K Herquet, P Hickford, S Hill, GC Hoffman, KD Homeier, A Hoshina, K Hubert, D Huelsnitz, W Hulss, JP Hulth, PO Hultqvist, K Hussain, S Ishihara, A Jacobsen, J Japaridze, GS Johansson, H Joseph, JM Kampert, KH Kappes, A Karg, T Karle, A Kenny, P Kiryluk, J Kislat, F Klein, SR Kohne, JH Kohnen, G Kolanoski, H Kopke, L Kopper, S Koskinen, DJ Kowalski, M Kowarik, T Krasberg, M Krings, T Kroll, G Kurahashi, N Kuwabara, T Labare, M Lafebre, S Laihem, K Landsman, H Larson, MJ Lauer, R Lunemann, J Madajczyk, B Madsen, J Majumdar, P Marotta, A Maruyama, R Mase, K Matis, HS Meagher, K Merck, M Meszaros, P Meures, T Middell, E Milke, N Miller, J Montaruli, T Morse, R Movit, SM Nahnhauer, R Nam, JW Naumann, U Niessen, P Nygren, DR Odrowski, S Olivas, A Olivo, M O'Murchadha, A Ono, M Panknin, S Paul, L de los Heros, CP Petrovic, J Piegsa, A Pieloth, D Porrata, R Posselt, J Price, CC Price, PB Przybylski, GT Rawlins, K Redl, P Resconi, E Rhode, W Ribordy, M Rizzo, A Rodrigues, JP Roth, P Rothmaier, F Rott, C Ruhe, T Rutledge, D Ruzybayev, B Ryckbosch, Dirk Sander, HG Santander, M Sarkar, S Schatto, K Schmidt, T Schonwald, A Schukraft, A Schultes, A Schulz, O Schunck, M Seckel, D Semburg, B Seo, SH Sestayo, Y Seunarine, S Silvestri, A Slipak, A Spiczak, GM Spiering, C Stamatikos, M Stanev, T Stephens, G Stezelberger, T Stokstad, RG Stossl, A Stoyanov, S Strahler, EA Straszheim, T Stur, M Sullivan, GW Swillens, Q Taavola, H Taboada, I Tamburro, A Tepe, A Ter-Antonyan, S Tilav, S Toale, PA Toscano, S Tosi, D Turcan, D van Eijndhoven, N Vandenbroucke, J Van Overloop, Arne van Santen, J Vehring, M Voge, M Walck, C Waldenmaier, T Wallraff, M Walter, M Weaver, C Wendt, C Westerhoff, S Whitehorn, N Wiebe, K Wiebusch, CH Williams, DR Wischnewski, R Wissing, H Wolf, M Wood, TR Woschnagg, K Xu, C Xu, XW Yodh, G Yoshida, S Zarzhitsky, P Zoll, M Observation of anisotropy in the arrival directions of galactic cosmic rays at multiple angular scales with IceCube |
topic_facet |
Physics and Astronomy astroparticle physics cosmic rays MILAGRO HOT-SPOTS AIR-SHOWER ARRAY ENERGY-SPECTRUM INTENSITY TELESCOPE ASTRONOMY |
description |
Between 2009 May and 2010 May, the IceCube neutrino detector at the South Pole recorded 32 billion muons generated in air showers produced by cosmic rays with a median energy of 20 TeV. With a data set of this size, it is possible to probe the southern sky for per-mil anisotropy on all angular scales in the arrival direction distribution of cosmic rays. Applying a power spectrum analysis to the relative intensity map of the cosmic ray flux in the southern hemisphere, we show that the arrival direction distribution is not isotropic, but shows significant structure on several angular scales. In addition to previously reported large-scale structure in the form of a strong dipole and quadrupole, the data show small-scale structure on scales between 15 degrees and 30 degrees. The skymap exhibits several localized regions of significant excess and deficit in cosmic ray intensity. The relative intensity of the smaller-scale structures is about a factor of five weaker than that of the dipole and quadrupole structure. The most significant structure, an excess localized at (right ascension alpha = 122 degrees.4 and declination d = -47 degrees.4), extends over at least 20 degrees in right ascension and has a post-trials significance of 5.3 sigma. The origin of this anisotropy is still unknown. |
format |
Article in Journal/Newspaper |
author |
Abbasi, R Abdou, Yasser Abu-Zayyad, T Adams, J Aguilar, JA Ahlers, M Altmann, D Andeen, K Auffenberg, J Bai, X Baker, M Barwick, SW Bay, R Alba, JLB Beattie, K Beatty, JJ Bechet, S Becker, JK Becker, KH Benabderrahmane, ML BenZvi, S Berdermann, J Berghaus, P Berley, D Bernardini, E Bertrand, D Besson, DZ Bindig, D Bissok, M Blaufuss, E Blumenthal, J Boersma, DJ Bohm, C Bose, D Boser, S Botner, O Brown, AM Buitink, S Caballero-Mora, KS Carson, Michael Chirkin, D Christy, B Clem, J Clevermann, F Cohen, S Colnard, C Cowen, DF D'Agostino, MV Danninger, M Daughhetee, J Davis, JC De Clercq, C Demirors, L Denger, T Depaepe, O Descamps, Freija Desiati, P De Vries-Uiterweerd, Garmt DeYoung, T Diaz-Velez, JC Dierckxsens, M Dreyer, J Dumm, JP Ehrlich, R Eisch, J Ellsworth, RW Engdegard, O Euler, S Evenson, PA Fadiran, O Fazely, AR Fedynitch, A Feintzeig, J Feusels, Tom Filimonov, K Finley, C Fischer-Wasels, T Foerster, MM Fox, BD Franckowiak, A Franke, R Gaisser, TK Gallagher, J Gerhardt, L Gladstone, L Glusenkamp, T Goldschmidt, A Goodman, JA Gora, D Grant, D Griesel, T Gross, A Grullon, S Gurtner, M Ha, C Haj Ismail, Abd Al Karim Hallgren, A Halzen, F Han, K Hanson, K Heinen, D Helbing, K Herquet, P Hickford, S Hill, GC Hoffman, KD Homeier, A Hoshina, K Hubert, D Huelsnitz, W Hulss, JP Hulth, PO Hultqvist, K Hussain, S Ishihara, A Jacobsen, J Japaridze, GS Johansson, H Joseph, JM Kampert, KH Kappes, A Karg, T Karle, A Kenny, P Kiryluk, J Kislat, F Klein, SR Kohne, JH Kohnen, G Kolanoski, H Kopke, L Kopper, S Koskinen, DJ Kowalski, M Kowarik, T Krasberg, M Krings, T Kroll, G Kurahashi, N Kuwabara, T Labare, M Lafebre, S Laihem, K Landsman, H Larson, MJ Lauer, R Lunemann, J Madajczyk, B Madsen, J Majumdar, P Marotta, A Maruyama, R Mase, K Matis, HS Meagher, K Merck, M Meszaros, P Meures, T Middell, E Milke, N Miller, J Montaruli, T Morse, R Movit, SM Nahnhauer, R Nam, JW Naumann, U Niessen, P Nygren, DR Odrowski, S Olivas, A Olivo, M O'Murchadha, A Ono, M Panknin, S Paul, L de los Heros, CP Petrovic, J Piegsa, A Pieloth, D Porrata, R Posselt, J Price, CC Price, PB Przybylski, GT Rawlins, K Redl, P Resconi, E Rhode, W Ribordy, M Rizzo, A Rodrigues, JP Roth, P Rothmaier, F Rott, C Ruhe, T Rutledge, D Ruzybayev, B Ryckbosch, Dirk Sander, HG Santander, M Sarkar, S Schatto, K Schmidt, T Schonwald, A Schukraft, A Schultes, A Schulz, O Schunck, M Seckel, D Semburg, B Seo, SH Sestayo, Y Seunarine, S Silvestri, A Slipak, A Spiczak, GM Spiering, C Stamatikos, M Stanev, T Stephens, G Stezelberger, T Stokstad, RG Stossl, A Stoyanov, S Strahler, EA Straszheim, T Stur, M Sullivan, GW Swillens, Q Taavola, H Taboada, I Tamburro, A Tepe, A Ter-Antonyan, S Tilav, S Toale, PA Toscano, S Tosi, D Turcan, D van Eijndhoven, N Vandenbroucke, J Van Overloop, Arne van Santen, J Vehring, M Voge, M Walck, C Waldenmaier, T Wallraff, M Walter, M Weaver, C Wendt, C Westerhoff, S Whitehorn, N Wiebe, K Wiebusch, CH Williams, DR Wischnewski, R Wissing, H Wolf, M Wood, TR Woschnagg, K Xu, C Xu, XW Yodh, G Yoshida, S Zarzhitsky, P Zoll, M |
author_facet |
Abbasi, R Abdou, Yasser Abu-Zayyad, T Adams, J Aguilar, JA Ahlers, M Altmann, D Andeen, K Auffenberg, J Bai, X Baker, M Barwick, SW Bay, R Alba, JLB Beattie, K Beatty, JJ Bechet, S Becker, JK Becker, KH Benabderrahmane, ML BenZvi, S Berdermann, J Berghaus, P Berley, D Bernardini, E Bertrand, D Besson, DZ Bindig, D Bissok, M Blaufuss, E Blumenthal, J Boersma, DJ Bohm, C Bose, D Boser, S Botner, O Brown, AM Buitink, S Caballero-Mora, KS Carson, Michael Chirkin, D Christy, B Clem, J Clevermann, F Cohen, S Colnard, C Cowen, DF D'Agostino, MV Danninger, M Daughhetee, J Davis, JC De Clercq, C Demirors, L Denger, T Depaepe, O Descamps, Freija Desiati, P De Vries-Uiterweerd, Garmt DeYoung, T Diaz-Velez, JC Dierckxsens, M Dreyer, J Dumm, JP Ehrlich, R Eisch, J Ellsworth, RW Engdegard, O Euler, S Evenson, PA Fadiran, O Fazely, AR Fedynitch, A Feintzeig, J Feusels, Tom Filimonov, K Finley, C Fischer-Wasels, T Foerster, MM Fox, BD Franckowiak, A Franke, R Gaisser, TK Gallagher, J Gerhardt, L Gladstone, L Glusenkamp, T Goldschmidt, A Goodman, JA Gora, D Grant, D Griesel, T Gross, A Grullon, S Gurtner, M Ha, C Haj Ismail, Abd Al Karim Hallgren, A Halzen, F Han, K Hanson, K Heinen, D Helbing, K Herquet, P Hickford, S Hill, GC Hoffman, KD Homeier, A Hoshina, K Hubert, D Huelsnitz, W Hulss, JP Hulth, PO Hultqvist, K Hussain, S Ishihara, A Jacobsen, J Japaridze, GS Johansson, H Joseph, JM Kampert, KH Kappes, A Karg, T Karle, A Kenny, P Kiryluk, J Kislat, F Klein, SR Kohne, JH Kohnen, G Kolanoski, H Kopke, L Kopper, S Koskinen, DJ Kowalski, M Kowarik, T Krasberg, M Krings, T Kroll, G Kurahashi, N Kuwabara, T Labare, M Lafebre, S Laihem, K Landsman, H Larson, MJ Lauer, R Lunemann, J Madajczyk, B Madsen, J Majumdar, P Marotta, A Maruyama, R Mase, K Matis, HS Meagher, K Merck, M Meszaros, P Meures, T Middell, E Milke, N Miller, J Montaruli, T Morse, R Movit, SM Nahnhauer, R Nam, JW Naumann, U Niessen, P Nygren, DR Odrowski, S Olivas, A Olivo, M O'Murchadha, A Ono, M Panknin, S Paul, L de los Heros, CP Petrovic, J Piegsa, A Pieloth, D Porrata, R Posselt, J Price, CC Price, PB Przybylski, GT Rawlins, K Redl, P Resconi, E Rhode, W Ribordy, M Rizzo, A Rodrigues, JP Roth, P Rothmaier, F Rott, C Ruhe, T Rutledge, D Ruzybayev, B Ryckbosch, Dirk Sander, HG Santander, M Sarkar, S Schatto, K Schmidt, T Schonwald, A Schukraft, A Schultes, A Schulz, O Schunck, M Seckel, D Semburg, B Seo, SH Sestayo, Y Seunarine, S Silvestri, A Slipak, A Spiczak, GM Spiering, C Stamatikos, M Stanev, T Stephens, G Stezelberger, T Stokstad, RG Stossl, A Stoyanov, S Strahler, EA Straszheim, T Stur, M Sullivan, GW Swillens, Q Taavola, H Taboada, I Tamburro, A Tepe, A Ter-Antonyan, S Tilav, S Toale, PA Toscano, S Tosi, D Turcan, D van Eijndhoven, N Vandenbroucke, J Van Overloop, Arne van Santen, J Vehring, M Voge, M Walck, C Waldenmaier, T Wallraff, M Walter, M Weaver, C Wendt, C Westerhoff, S Whitehorn, N Wiebe, K Wiebusch, CH Williams, DR Wischnewski, R Wissing, H Wolf, M Wood, TR Woschnagg, K Xu, C Xu, XW Yodh, G Yoshida, S Zarzhitsky, P Zoll, M |
author_sort |
Abbasi, R |
title |
Observation of anisotropy in the arrival directions of galactic cosmic rays at multiple angular scales with IceCube |
title_short |
Observation of anisotropy in the arrival directions of galactic cosmic rays at multiple angular scales with IceCube |
title_full |
Observation of anisotropy in the arrival directions of galactic cosmic rays at multiple angular scales with IceCube |
title_fullStr |
Observation of anisotropy in the arrival directions of galactic cosmic rays at multiple angular scales with IceCube |
title_full_unstemmed |
Observation of anisotropy in the arrival directions of galactic cosmic rays at multiple angular scales with IceCube |
title_sort |
observation of anisotropy in the arrival directions of galactic cosmic rays at multiple angular scales with icecube |
publishDate |
2011 |
url |
https://biblio.ugent.be/publication/2146317 http://hdl.handle.net/1854/LU-2146317 https://doi.org/10.1088/0004-637X/740/1/16 https://biblio.ugent.be/publication/2146317/file/2946458 |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_source |
ASTROPHYSICAL JOURNAL ISSN: 0004-637X |
op_relation |
https://biblio.ugent.be/publication/2146317 http://hdl.handle.net/1854/LU-2146317 http://dx.doi.org/10.1088/0004-637X/740/1/16 https://biblio.ugent.be/publication/2146317/file/2946458 |
op_rights |
No license (in copyright) info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1088/0004-637X/740/1/16 |
container_title |
The Astrophysical Journal |
container_volume |
740 |
container_issue |
1 |
container_start_page |
16 |
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1778533628166275072 |
spelling |
ftunivgent:oai:archive.ugent.be:2146317 2023-10-01T03:59:31+02:00 Observation of anisotropy in the arrival directions of galactic cosmic rays at multiple angular scales with IceCube Abbasi, R Abdou, Yasser Abu-Zayyad, T Adams, J Aguilar, JA Ahlers, M Altmann, D Andeen, K Auffenberg, J Bai, X Baker, M Barwick, SW Bay, R Alba, JLB Beattie, K Beatty, JJ Bechet, S Becker, JK Becker, KH Benabderrahmane, ML BenZvi, S Berdermann, J Berghaus, P Berley, D Bernardini, E Bertrand, D Besson, DZ Bindig, D Bissok, M Blaufuss, E Blumenthal, J Boersma, DJ Bohm, C Bose, D Boser, S Botner, O Brown, AM Buitink, S Caballero-Mora, KS Carson, Michael Chirkin, D Christy, B Clem, J Clevermann, F Cohen, S Colnard, C Cowen, DF D'Agostino, MV Danninger, M Daughhetee, J Davis, JC De Clercq, C Demirors, L Denger, T Depaepe, O Descamps, Freija Desiati, P De Vries-Uiterweerd, Garmt DeYoung, T Diaz-Velez, JC Dierckxsens, M Dreyer, J Dumm, JP Ehrlich, R Eisch, J Ellsworth, RW Engdegard, O Euler, S Evenson, PA Fadiran, O Fazely, AR Fedynitch, A Feintzeig, J Feusels, Tom Filimonov, K Finley, C Fischer-Wasels, T Foerster, MM Fox, BD Franckowiak, A Franke, R Gaisser, TK Gallagher, J Gerhardt, L Gladstone, L Glusenkamp, T Goldschmidt, A Goodman, JA Gora, D Grant, D Griesel, T Gross, A Grullon, S Gurtner, M Ha, C Haj Ismail, Abd Al Karim Hallgren, A Halzen, F Han, K Hanson, K Heinen, D Helbing, K Herquet, P Hickford, S Hill, GC Hoffman, KD Homeier, A Hoshina, K Hubert, D Huelsnitz, W Hulss, JP Hulth, PO Hultqvist, K Hussain, S Ishihara, A Jacobsen, J Japaridze, GS Johansson, H Joseph, JM Kampert, KH Kappes, A Karg, T Karle, A Kenny, P Kiryluk, J Kislat, F Klein, SR Kohne, JH Kohnen, G Kolanoski, H Kopke, L Kopper, S Koskinen, DJ Kowalski, M Kowarik, T Krasberg, M Krings, T Kroll, G Kurahashi, N Kuwabara, T Labare, M Lafebre, S Laihem, K Landsman, H Larson, MJ Lauer, R Lunemann, J Madajczyk, B Madsen, J Majumdar, P Marotta, A Maruyama, R Mase, K Matis, HS Meagher, K Merck, M Meszaros, P Meures, T Middell, E Milke, N Miller, J Montaruli, T Morse, R Movit, SM Nahnhauer, R Nam, JW Naumann, U Niessen, P Nygren, DR Odrowski, S Olivas, A Olivo, M O'Murchadha, A Ono, M Panknin, S Paul, L de los Heros, CP Petrovic, J Piegsa, A Pieloth, D Porrata, R Posselt, J Price, CC Price, PB Przybylski, GT Rawlins, K Redl, P Resconi, E Rhode, W Ribordy, M Rizzo, A Rodrigues, JP Roth, P Rothmaier, F Rott, C Ruhe, T Rutledge, D Ruzybayev, B Ryckbosch, Dirk Sander, HG Santander, M Sarkar, S Schatto, K Schmidt, T Schonwald, A Schukraft, A Schultes, A Schulz, O Schunck, M Seckel, D Semburg, B Seo, SH Sestayo, Y Seunarine, S Silvestri, A Slipak, A Spiczak, GM Spiering, C Stamatikos, M Stanev, T Stephens, G Stezelberger, T Stokstad, RG Stossl, A Stoyanov, S Strahler, EA Straszheim, T Stur, M Sullivan, GW Swillens, Q Taavola, H Taboada, I Tamburro, A Tepe, A Ter-Antonyan, S Tilav, S Toale, PA Toscano, S Tosi, D Turcan, D van Eijndhoven, N Vandenbroucke, J Van Overloop, Arne van Santen, J Vehring, M Voge, M Walck, C Waldenmaier, T Wallraff, M Walter, M Weaver, C Wendt, C Westerhoff, S Whitehorn, N Wiebe, K Wiebusch, CH Williams, DR Wischnewski, R Wissing, H Wolf, M Wood, TR Woschnagg, K Xu, C Xu, XW Yodh, G Yoshida, S Zarzhitsky, P Zoll, M 2011 application/pdf https://biblio.ugent.be/publication/2146317 http://hdl.handle.net/1854/LU-2146317 https://doi.org/10.1088/0004-637X/740/1/16 https://biblio.ugent.be/publication/2146317/file/2946458 eng eng https://biblio.ugent.be/publication/2146317 http://hdl.handle.net/1854/LU-2146317 http://dx.doi.org/10.1088/0004-637X/740/1/16 https://biblio.ugent.be/publication/2146317/file/2946458 No license (in copyright) info:eu-repo/semantics/restrictedAccess ASTROPHYSICAL JOURNAL ISSN: 0004-637X Physics and Astronomy astroparticle physics cosmic rays MILAGRO HOT-SPOTS AIR-SHOWER ARRAY ENERGY-SPECTRUM INTENSITY TELESCOPE ASTRONOMY journalArticle info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2011 ftunivgent https://doi.org/10.1088/0004-637X/740/1/16 2023-09-06T22:36:35Z Between 2009 May and 2010 May, the IceCube neutrino detector at the South Pole recorded 32 billion muons generated in air showers produced by cosmic rays with a median energy of 20 TeV. With a data set of this size, it is possible to probe the southern sky for per-mil anisotropy on all angular scales in the arrival direction distribution of cosmic rays. Applying a power spectrum analysis to the relative intensity map of the cosmic ray flux in the southern hemisphere, we show that the arrival direction distribution is not isotropic, but shows significant structure on several angular scales. In addition to previously reported large-scale structure in the form of a strong dipole and quadrupole, the data show small-scale structure on scales between 15 degrees and 30 degrees. The skymap exhibits several localized regions of significant excess and deficit in cosmic ray intensity. The relative intensity of the smaller-scale structures is about a factor of five weaker than that of the dipole and quadrupole structure. The most significant structure, an excess localized at (right ascension alpha = 122 degrees.4 and declination d = -47 degrees.4), extends over at least 20 degrees in right ascension and has a post-trials significance of 5.3 sigma. The origin of this anisotropy is still unknown. Article in Journal/Newspaper South pole Ghent University Academic Bibliography South Pole The Astrophysical Journal 740 1 16 |