OBSERVATION OF ANISOTROPY IN THE ARRIVAL DIRECTIONS OF GALACTIC COSMIC RAYS AT MULTIPLE ANGULAR SCALES WITH IceCube

被引:98
作者
Abbasi, R. [1 ]
Abdou, Y. [2 ]
Abu-Zayyad, T. [3 ]
Adams, J. [4 ]
Aguilar, J. A. [1 ]
Ahlers, M. [5 ]
Altmann, D. [6 ]
Andeen, K. [1 ]
Auffenberg, J. [7 ]
Bai, X. [8 ,9 ]
Baker, M. [1 ]
Barwick, S. W. [10 ]
Bay, R. [11 ]
Alba, J. L. Bazo [12 ]
Beattie, K. [13 ]
Beatty, J. J. [14 ,15 ,16 ]
Bechet, S. [17 ]
Becker, J. K. [18 ]
Becker, K. -H. [7 ]
Benabderrahmane, M. L. [12 ]
BenZvi, S. [1 ]
Berdermann, J. [12 ]
Berghaus, P. [8 ,9 ]
Berley, D. [19 ]
Bernardini, E. [12 ]
Bertrand, D. [17 ]
Besson, D. Z. [20 ]
Bindig, D. [7 ]
Bissok, M. [6 ]
Blaufuss, E. [19 ]
Blumenthal, J. [6 ]
Boersma, D. J. [6 ]
Bohm, C. [21 ,22 ]
Bose, D. [23 ]
Boeser, S. [24 ]
Botner, O. [25 ]
Brown, A. M. [4 ]
Buitink, S. [23 ]
Caballero-Mora, K. S. [26 ]
Carson, M. [2 ]
Chirkin, D. [1 ]
Christy, B. [19 ]
Clem, J. [8 ,9 ]
Clevermann, F. [27 ]
Cohen, S. [28 ]
Colnard, C. [29 ]
Cowen, D. F. [26 ,30 ]
D'Agostino, M. V. [11 ]
Danninger, M. [21 ,22 ]
Daughhetee, J. [31 ,32 ]
机构
[1] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA
[2] Univ Ghent, Dept Phys & Astron, B-9000 Ghent, Belgium
[3] Univ Wisconsin, Dept Phys, River Falls, WI 54022 USA
[4] Univ Canterbury, Dept Phys & Astron, Christchurch 1, New Zealand
[5] Univ Oxford, Dept Phys, Oxford OX1 3NP, England
[6] Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany
[7] Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany
[8] Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA
[9] Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA
[10] Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA
[11] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA
[12] DESY, D-15735 Zeuthen, Germany
[13] Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA
[14] Ohio State Univ, Dept Phys, Columbus, OH 43210 USA
[15] Ohio State Univ, Ctr Cosmol & Astroparticle, Columbus, OH 43210 USA
[16] Ohio State Univ, Dept Astron, Columbus, OH 43210 USA
[17] Univ Libre Bruxelles, Fac Sci, B-1050 Brussels, Belgium
[18] Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany
[19] Univ Maryland, Dept Phys, College Pk, MD 20742 USA
[20] Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA
[21] Stockholm Univ, Dept Phys, SE-10691 Stockholm, Sweden
[22] Stockholm Univ, Oskar Klein Ctr, SE-10691 Stockholm, Sweden
[23] Vrije Univ Brussel, Dienst ELEM, B-1050 Brussels, Belgium
[24] Univ Bonn, Inst Phys, D-53115 Bonn, Germany
[25] Uppsala Univ, Dept Phys & Astron, S-75120 Uppsala, Sweden
[26] Penn State Univ, Dept Phys, University Pk, PA 16802 USA
[27] TU Dortmund Univ, Dept Phys, D-44221 Dortmund, Germany
[28] Ecole Polytech Fed Lausanne, High Energy Phys Lab, CH-1015 Lausanne, Switzerland
[29] Max Planck Inst Kernphys, D-69177 Heidelberg, Germany
[30] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA
[31] Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA
[32] Georgia Inst Technol, Ctr Relativist Astrophys, Atlanta, GA 30332 USA
[33] Clark Atlanta Univ, CTSPS, Atlanta, GA 30314 USA
[34] Southern Univ, Dept Phys, Baton Rouge, LA 70813 USA
[35] Univ Wisconsin, Dept Astron, Madison, WI 53706 USA
[36] Univ Alberta, Dept Phys, Edmonton, AB T6G 2G7, Canada
[37] Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany
[38] Univ Mons, B-7000 Mons, Belgium
[39] Chiba Univ, Dept Phys, Chiba 2638522, Japan
[40] Humboldt Univ, Inst Phys, D-12489 Berlin, Germany
[41] Univ Bari, Dipartmento Fis, I-70126 Bari, Italy
[42] Sezione Ist Nazl Fis Nucl, Bari, Italy
[43] Univ Alaska, Dept Phys & Astron, Anchorage, AK 99508 USA
[44] Univ W Indies, Dept Phys, BB-11000 Bridgetown, Barbados
[45] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[46] Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA
基金
美国国家科学基金会; 瑞典研究理事会; 瑞士国家科学基金会;
关键词
astroparticle physics; cosmic rays; MILAGRO HOT-SPOTS; AIR-SHOWER ARRAY; ENERGY-SPECTRUM; INTENSITY; TELESCOPE; ASTRONOMY;
D O I
10.1088/0004-637X/740/1/16
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
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.
引用
收藏
页数:17
相关论文
共 37 条
[1]   MEASUREMENT OF THE ANISOTROPY OF COSMIC-RAY ARRIVAL DIRECTIONS WITH ICECUBE [J].
Abbasi, R. ;
Abdou, Y. ;
Abu-Zayyad, T. ;
Adams, J. ;
Aguilar, J. A. ;
Ahlers, M. ;
Andeen, K. ;
Auffenberg, J. ;
Bai, X. ;
Baker, M. ;
Barwick, S. W. ;
Bay, R. ;
Alba, J. L. Bazo ;
Beattie, K. ;
Beatty, J. J. ;
Bechet, S. ;
Becker, J. K. ;
Becker, K. -H. ;
Benabderrahmane, M. L. ;
BenZvi, S. ;
Berdermann, J. ;
Berghaus, P. ;
Berley, D. ;
Bernardini, E. ;
Bertrand, D. ;
Besson, D. Z. ;
Bissok, M. ;
Blaufuss, E. ;
Boersma, D. J. ;
Bohm, C. ;
Boeser, S. ;
Botner, O. ;
Bradley, L. ;
Braun, J. ;
Buitink, S. ;
Carson, M. ;
Chirkin, D. ;
Christy, B. ;
Clem, J. ;
Clevermann, F. ;
Cohen, S. ;
Colnard, C. ;
Cowen, D. F. ;
D'Agostino, M. V. ;
Danninger, M. ;
Davis, J. C. ;
De Clercq, C. ;
Demiroers, L. ;
Depaepe, O. ;
Descamps, F. .
ASTROPHYSICAL JOURNAL LETTERS, 2010, 718 (02) :L194-L198
[2]   Calibration and characterization of the IceCube photomultiplier tube [J].
Abbasi, R. ;
Abdou, Y. ;
Abu-Zayyad, T. ;
Adams, J. ;
Aguilar, J. A. ;
Ahlers, M. ;
Andeen, K. ;
Auffenberg, J. ;
Bai, X. ;
Baker, M. ;
Barwick, S. W. ;
Bay, R. ;
Alba, J. L. Bazo ;
Beattie, K. ;
Beatty, J. J. ;
Bechet, S. ;
Becker, J. K. ;
Becker, K. -H. ;
Benabderrahmane, M. L. ;
Berdermann, J. ;
Berghaus, P. ;
Berley, D. ;
Bernardini, E. ;
Bertrand, D. ;
Besson, D. Z. ;
Bissok, M. ;
Blaufuss, E. ;
Boersma, D. J. ;
Bohm, C. ;
Botner, O. ;
Bradley, L. ;
Braun, J. ;
Buitink, S. ;
Carson, M. ;
Chirkin, D. ;
Christy, B. ;
Clem, J. ;
Cohen, S. ;
Colnard, C. ;
Cowen, D. F. ;
D'Agostino, M. V. ;
Danninger, M. ;
De Clercq, C. ;
Demiroers, L. ;
Depaepe, O. ;
Descamps, F. ;
Desiati, P. ;
de Vries-Uiterweerd, G. ;
DeYoung, T. ;
Diaz-Velez, J. C. .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 2010, 618 (1-3) :139-152
[3]   FIRST NEUTRINO POINT-SOURCE RESULTS FROM THE 22 STRING ICECUBE DETECTOR [J].
Abbasi, R. ;
Abdou, Y. ;
Ackermann, M. ;
Adams, J. ;
Aguilar, J. ;
Ahlers, M. ;
Andeen, K. ;
Auffenberg, J. ;
Bai, X. ;
Baker, M. ;
Barwick, S. W. ;
Bay, R. ;
Alba, J. L. Bazo ;
Beattie, K. ;
Beatty, J. J. ;
Bechet, S. ;
Becker, J. K. ;
Becker, K. -H. ;
Benabderrahmane, M. L. ;
Berdermann, J. ;
Berghaus, P. ;
Berley, D. ;
Bernardini, E. ;
Bertrand, D. ;
Besson, D. Z. ;
Bissok, M. ;
Blaufuss, E. ;
Boersma, D. J. ;
Bohm, C. ;
Bolmont, J. ;
Boeser, S. ;
Botner, O. ;
Bradley, L. ;
Braun, J. ;
Breder, D. ;
Castermans, T. ;
Chirkin, D. ;
Christy, B. ;
Clem, J. ;
Cohen, S. ;
Cowen, D. F. ;
D'Agostino, M. V. ;
Danninger, M. ;
Day, C. T. ;
De Clercq, C. ;
Demiroers, L. ;
Depaepe, O. ;
Descamps, F. ;
Desiati, P. ;
de Vries-Uiterweerd, G. .
ASTROPHYSICAL JOURNAL LETTERS, 2009, 701 (01) :L47-L51
[4]   The IceCube data acquisition system: Signal capture, digitization, and timestamping [J].
Abbasi, R. ;
Ackermann, M. ;
Adams, J. ;
Ahlers, M. ;
Ahrens, J. ;
Andeen, K. ;
Auffenberge, J. ;
Bai, X. ;
Baker, M. ;
Barwick, S. W. ;
Bay, R. ;
Alba, J. L. Bazo ;
Beattie, K. ;
Becka, T. ;
Becker, J. K. ;
Becker, K-H. ;
Berghaus, P. ;
Berley, D. ;
Bernardini, E. ;
Bertrand, D. ;
Besson, D. Z. ;
Bingham, B. ;
Blaufuss, E. ;
Boersma, D. J. ;
Bohm, C. ;
Bolmont, J. ;
Boeser, S. ;
Botner, O. ;
Braun, J. ;
Breeder, D. ;
Burgess, T. ;
Carithers, W. ;
Castermans, T. ;
Chen, H. ;
Chirkin, D. ;
Christy, B. ;
Clem, J. ;
Cowen, D. F. ;
D'Agostino, M. V. ;
Danninger, M. ;
Davour, A. ;
Day, C. T. ;
Depaepe, O. ;
De Clercq, C. ;
Demiroers, L. ;
Descamps, F. ;
Desiati, P. ;
de Vries-Uiterweerd, G. ;
DeYoung, T. ;
Diaz-Velez, J. C. .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 2009, 601 (03) :294-316
[5]   Discovery of Localized Regions of Excess 10-TeV Cosmic Rays [J].
Abdo, A. A. ;
Allen, B. ;
Aune, T. ;
Berley, D. ;
Blaufuss, E. ;
Casanova, S. ;
Chen, C. ;
Dingus, B. L. ;
Ellsworth, R. W. ;
Fleysher, L. ;
Fleysher, R. ;
Gonzalez, M. M. ;
Goodman, J. A. ;
Hoffman, C. M. ;
Huentemeyer, P. H. ;
Kolterman, B. E. ;
Lansdell, C. P. ;
Linnemann, J. T. ;
McEnery, J. E. ;
Mincer, A. I. ;
Nemethy, P. ;
Noyes, D. ;
Pretz, J. ;
Ryan, J. M. ;
Parkinson, P. M. Saz ;
Shoup, A. ;
Sinnis, G. ;
Smith, A. J. ;
Sullivan, G. W. ;
Vasileiou, V. ;
Walker, G. P. ;
Williams, D. A. ;
Yodh, G. B. .
PHYSICAL REVIEW LETTERS, 2008, 101 (22)
[6]   THE LARGE-SCALE COSMIC-RAY ANISOTROPY AS OBSERVED WITH MILAGRO [J].
Abdo, A. A. ;
Allen, B. T. ;
Aune, T. ;
Berley, D. ;
Casanova, S. ;
Chen, C. ;
Dingus, B. L. ;
Ellsworth, R. W. ;
Fleysher, L. ;
Fleysher, R. ;
Gonzalez, M. M. ;
Goodman, J. A. ;
Hoffman, C. M. ;
Hopper, B. ;
Huentemeyer, P. H. ;
Kolterman, B. E. ;
Lansdell, C. P. ;
Linnemann, J. T. ;
McEnery, J. E. ;
Mincer, A. I. ;
Nemethy, P. ;
Noyes, D. ;
Pretz, J. ;
Ryan, J. M. ;
Parkinson, P. M. Saz ;
Shoup, A. ;
Sinnis, G. ;
Smith, A. J. ;
Sullivan, G. W. ;
Vasileiou, V. ;
Walker, G. P. ;
Williams, D. A. ;
Yodh, G. B. .
ASTROPHYSICAL JOURNAL, 2009, 698 (02) :2121-2130
[7]   First year performance of the IceCube neutrino telescope [J].
Achterberg, A. ;
Ackermann, M. ;
Adams, J. ;
Ahrens, J. ;
Andeen, K. ;
Atlee, D. W. ;
Baccus, J. ;
Bahcall, J. N. ;
Bai, X. ;
Baret, B. ;
Bartelt, M. ;
Barwick, S. W. ;
Bay, R. ;
Beattie, K. ;
Becka, T. ;
Becker, J. K. ;
Becker, K. -H. ;
Berghaus, P. ;
Berley, D. ;
Bernardini, E. ;
Bertrand, D. ;
Besson, D. Z. ;
Blaufuss, E. ;
Boersma, D. J. ;
Boeser, S. ;
Botner, O. ;
Bouchta, A. ;
Braun, J. ;
Burgess, C. ;
Burgess, T. ;
Castermans, T. ;
Cherwinka, J. ;
Chirkin, D. ;
Clem, J. ;
Cowen, D. F. ;
D'Agostino, M. V. ;
Davour, A. ;
Day, C. T. ;
De Clercq, C. ;
Demiroer, L. ;
Desiati, P. ;
DeYoung, T. ;
Diaz-Velez, J. C. ;
Dreyer, J. ;
Duvoort, M. R. ;
Edwards, W. R. ;
Ehrlich, R. ;
Eisch, J. ;
Elcheikh, A. ;
Ellsworth, R. W. .
ASTROPARTICLE PHYSICS, 2006, 26 (03) :155-173
[8]   EVOLUTION OF THE COSMIC-RAY ANISOTROPY ABOVE 1014 eV [J].
Aglietta, M. ;
Alekseenko, V. V. ;
Alessandro, B. ;
Antonioli, P. ;
Arneodo, F. ;
Bergamasco, L. ;
Bertaina, M. ;
Bonino, R. ;
Castellina, A. ;
Chiavassa, A. ;
Piazzoli, B. D'Ettorre ;
Di Sciascio, G. ;
Fulgione, W. ;
Galeotti, P. ;
Ghia, P. L. ;
Iacovacci, M. ;
Mannocchi, G. ;
Morello, C. ;
Navarra, G. ;
Saavedra, O. ;
Stamerra, A. ;
Trinchero, G. C. ;
Valchierotti, S. ;
Vallania, P. ;
Vernetto, S. ;
Vigorito, C. .
ASTROPHYSICAL JOURNAL LETTERS, 2009, 692 (02) :L130-L133
[9]   Cosmic ray interaction event generator SIBYLL 2.1 [J].
Ahn, Eun-Joo ;
Engel, Ralph ;
Gaisser, Thomas K. ;
Lipari, Paolo ;
Stanev, Todor .
PHYSICAL REVIEW D, 2009, 80 (09)
[10]   Muon track reconstruction and data selection techniques in AMANDA [J].
Ahrens, J ;
Bai, X ;
Bay, R ;
Barwick, SW ;
Becka, T ;
Becker, JK ;
Becker, KH ;
Bernardini, E ;
Bertrand, D ;
Biron, A ;
Boersma, DJ ;
Böser, S ;
Botner, O ;
Bouchta, A ;
Bouhali, O ;
Burgess, T ;
Carius, S ;
Castermans, T ;
Chirkin, D ;
Collin, B ;
Conrad, J ;
Cooley, J ;
Cowen, DF ;
Davour, A ;
De Clercq, C ;
DeYoung, T ;
Desitati, P ;
Dewulf, JP ;
Ekström, P ;
Feser, T ;
Gaug, M ;
Gaisser, TK ;
Ganugapati, R ;
Geenen, H ;
Gerhardt, L ;
Gross, A ;
Goldschmidt, A ;
Hallgren, A ;
Halzen, F ;
Hanson, K ;
Hardtke, R ;
Harenberg, T ;
Hauschildt, T ;
Helbing, K ;
Hellwig, M ;
Herquet, P ;
Hill, GC ;
Hubert, D ;
Hughey, B ;
Hulth, PO .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 2004, 524 (1-3) :169-194