FASER2

Research group

Research theme

Sub department

About

Observation of Anisotropy in the Arrival Directions of Galactic Cosmic Rays at Multiple Angular Scales with IceCube

ArXiv 1105.2326 (2011)

Authors:

IceCube Collaboration, R Abbasi, Y Abdou, T Abu-Zayyad, J Adams, JA Aguilar, M Ahlers, D Altmann, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, K-H Becker, ML Benabderrahmane, S BenZvi, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, AM Brown, S Buitink, KS Caballero-Mora, M Carson, D Chirkin, B Christy, J Clem, F Clevermann, S Cohen, C Colnard, DF Cowen, MV D'Agostino, M Danninger, J Daughhetee, JC Davis, C De Clercq, L Demirörs, T Denger, O Depaepe, F Descamps, P Desiati, G de Vries-Uiterweerd, T DeYoung, JC Díaz-Vélez, M Dierckxsens, J Dreyer, JP Dumm, R Ehrlich, J Eisch, RW Ellsworth, O Engdegård, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, J Feintzeig, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, MM Foerster, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Gora, D Grant, T Griesel, A Groß, S Grullon, M Gurtner, C Ha, A Hajismail, A Hallgren, F Halzen, K Han, K Hanson, D Heinen, K Helbing, P Herquet, S Hickford, GC Hill, KD Hoffman, A Homeier, K Hoshina, D Hubert, W Huelsnitz, J-P Hülß, PO Hulth, K Hultqvist, S Hussain, A Ishihara, J Jacobsen, GS Japaridze, H Johansson, JM Joseph, K-H Kampert, A Kappes, T Karg, A Karle, P Kenny, J Kiryluk, F Kislat, SR Klein, J-H Köhne, G Kohnen, H Kolanoski, L Köpke, S Kopper, DJ Koskinen, M Kowalski, T Kowarik, M Krasberg, T Krings, G Kroll, N Kurahashi, T Kuwabara, M Labare, S Lafebre, K Laihem, H Landsman, MJ Larson, R Lauer, J Lünemann, B Madajczyk, J Madsen, P Majumdar, A Marotta, R Maruyama, K Mase, HS Matis, K Meagher, M Merck, P Mészáros, T Meures, E Middell, N Milke, J Miller, T Montaruli, R Morse, SM Movit, R Nahnhauer, JW Nam, U Naumann, P Nießen, DR Nygren, S Odrowski, A Olivas, M Olivo, A O'Murchadha, M Ono, S Panknin, L Paul, C Pérez de los Heros, J Petrovic, A Piegsa, D Pieloth, R Porrata, J Posselt, CC Price, PB Price, GT Przybylski, K Rawlins, P Redl, E Resconi, W Rhode, M Ribordy, A Rizzo, JP Rodrigues, P Roth, F Rothmaier, C Rott, T Ruhe, D Rutledge, B Ruzybayev, D Ryckbosch, H-G Sander, M Santander, S Sarkar, K Schatto, T Schmidt, A Schönwald, A Schukraft, A Schultes, O Schulz, M Schunck, D Seckel, B Semburg, SH Seo, Y Sestayo, S Seunarine, A Silvestri, A Slipak, GM Spiczak, C Spiering, M Stamatikos, T Stanev, G Stephens, T Stezelberger, RG Stokstad, A Stössl, S Stoyanov, EA Strahler, T Straszheim, M Stür, GW Sullivan, Q Swillens, H Taavola, I Taboada, A Tamburro, A Tepe, S Ter-Antonyan, S Tilav, PA Toale, S Toscano, D Tosi, D Turčan, N van Eijndhoven, J Vandenbroucke, A Van Overloop, J van Santen, M Vehring, M Voge, C Walck, T Waldenmaier, M Wallraff, M Walter, Ch Weaver, C Wendt, S Westerhoff, N Whitehorn, K Wiebe, CH Wiebusch, DR Williams, R Wischnewski, H Wissing, M Wolf, TR Wood, K Woschnagg, C Xu, XW Xu, G Yodh, S Yoshida, P Zarzhitsky, M Zoll

Abstract:

Between May 2009 and May 2010, 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-mille 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 5 weaker than that of the dipole and quadrupole structure. The most significant structure, an excess localized at right ascension 122.4 degrees and declination -47.4 degrees, 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.
Details from ArXiV
More details from the publisher

A Search for a Diffuse Flux of Astrophysical Muon Neutrinos with the IceCube 40-String Detector

ArXiv 1104.5187 (2011)

Authors:

IceCube Collaboration, R Abbasi, Y Abdou, T Abu-Zayyad, J Adams, JA Aguilar, M Ahlers, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, K-H Becker, ML Benabderrahmane, S BenZvi, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, J Braun, AM Brown, S Buitink, M Carson, D Chirkin, B Christy, J Clem, F Clevermann, S Cohen, C Colnard, DF Cowen, MV D'Agostino, M Danninger, J Daughhetee, JC Davis, C De Clercq, L Demirörs, T Denger, O Depaepe, F Descamps, P Desiati, G de Vries-Uiterweerd, T DeYoung, JC Díaz-Vélez, M Dierckxsens, J Dreyer, JP Dumm, R Ehrlich, J Eisch, RW Ellsworth, O Engdegård, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, MM Foerster, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, M Geisler, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Gora, D Grant, T Griesel, A Groß, S Grullon, M Gurtner, C Ha, A Hallgren, F Halzen, K Han, K Hanson, D Heinen, K Helbing, P Herquet, S Hickford, GC Hill, KD Hoffman, A Homeier, K Hoshina, D Hubert, W Huelsnitz, J-P Hülß, PO Hulth, K Hultqvist, S Hussain, A Ishihara, J Jacobsen, GS Japaridze, H Johansson, JM Joseph, K-H Kampert, A Kappes, T Karg, A Karle, JL Kelley, P Kenny, J Kiryluk, F Kislat, SR Klein, J-H Köhne, G Kohnen, H Kolanoski, L Köpke, S Kopper, DJ Koskinen, M Kowalski, T Kowarik, M Krasberg, T Krings, G Kroll, T Kuwabara, M Labare, S Lafebre, K Laihem, H Landsman, MJ Larson, R Lauer, J Lünemann, J Madsen, P Majumdar, A Marotta, R Maruyama, K Mase, HS Matis, K Meagher, M Merck, P Mészáros, T Meures, E Middell, N Milke, J Miller, T Montaruli, R Morse, SM Movit, R Nahnhauer, JW Nam, U Naumann, P Nießen, DR Nygren, S Odrowski, A Olivas, M Olivo, A O'Murchadha, M Ono, S Panknin, L Paul, C Pérez de los Heros, J Petrovic, A Piegsa, D Pieloth, R Porrata, J Posselt, PB Price, GT Przybylski, K Rawlins, P Redl, E Resconi, W Rhode, M Ribordy, A Rizzo, JP Rodrigues, P Roth, F Rothmaier, C Rott, T Ruhe, D Rutledge, B Ruzybayev, D Ryckbosch, H-G Sander, M Santander, S Sarkar, K Schatto, T Schmidt, A Schönwald, A Schukraft, A Schultes, O Schulz, M Schunck, D Seckel, B Semburg, SH Seo, Y Sestayo, S Seunarine, A Silvestri, A Slipak, GM Spiczak, C Spiering, M Stamatikos, T Stanev, G Stephens, T Stezelberger, RG Stokstad, A Stössl, S Stoyanov, EA Strahler, T Straszheim, M Stür, GW Sullivan, Q Swillens, H Taavola, I Taboada, A Tamburro, A Tepe, S Ter-Antonyan, S Tilav, PA Toale, S Toscano, D Tosi, D Turčan, N van Eijndhoven, J Vandenbroucke, A Van Overloop, J van Santen, M Vehring, M Voge, C Walck, T Waldenmaier, M Wallraff, M Walter, Ch Weaver, C Wendt, S Westerhoff, N Whitehorn, K Wiebe, CH Wiebusch, DR Williams, R Wischnewski, H Wissing, M Wolf, TR Wood, K Woschnagg, C Xu, XW Xu, G Yodh, S Yoshida, P Zarzhitsky

Abstract:

The IceCube Neutrino Observatory is a 1 km$^{3}$ detector currently taking data at the South Pole. One of the main strategies used to look for astrophysical neutrinos with IceCube is the search for a diffuse flux of high-energy neutrinos from unresolved sources. A hard energy spectrum of neutrinos from isotropically distributed astrophysical sources could manifest itself as a detectable signal that may be differentiated from the atmospheric neutrino background by spectral measurement. This analysis uses data from the IceCube detector collected in its half completed configuration which operated between April 2008 and May 2009 to search for a diffuse flux of astrophysical muon neutrinos. A total of 12,877 upward going candidate neutrino events have been selected for this analysis. No evidence for a diffuse flux of astrophysical muon neutrinos was found in the data set leading to a 90 percent C.L. upper limit on the normalization of an $E^{-2}$ astrophysical $\nu_{\mu}$ flux of $8.9 \times 10^{-9} \ \mathrm{GeV \ cm^{-2} \ s^{-1} \ sr^{-1}}$. The analysis is sensitive in the energy range between $35 \ \mathrm{TeV} - 7 \ \mathrm{PeV}$. The 12,877 candidate neutrino events are consistent with atmospheric muon neutrinos measured from 332 GeV to 84 TeV and no evidence for a prompt component to the atmospheric neutrino spectrum is found.
Details from ArXiV
More details from the publisher

Fermi gamma-ray `bubbles' from stochastic acceleration of electrons

(2011)

Authors:

Philipp Mertsch, Subir Sarkar
More details from the publisher

Limits on neutrino emission from gamma-ray bursts with the 40 string IceCube detector.

Phys Rev Lett 106:14 (2011) 141101

Authors:

R Abbasi, Y Abdou, T Abu-Zayyad, J Adams, JA Aguilar, M Ahlers, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, K-H Becker, ML Benabderrahmane, S BenZvi, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, J Braun, AM Brown, S Buitink, M Carson, D Chirkin, B Christy, J Clem, F Clevermann, S Cohen, C Colnard, DF Cowen, MV D'Agostino, M Danninger, J Daughhetee, JC Davis, C De Clercq, L Demirörs, O Depaepe, F Descamps, P Desiati, G de Vries-Uiterweerd, T DeYoung, JC Díaz-Vélez, M Dierckxsens, J Dreyer, JP Dumm, R Ehrlich, J Eisch, RW Ellsworth, O Engdegård, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, MM Foerster, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, M Geisler, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Grant, T Griesel, A Gross, S Grullon, M Gurtner, C Ha, A Hallgren, F Halzen, K Han, K Hanson, D Heinen, K Helbing, P Herquet, S Hickford, GC Hill, KD Hoffman, A Homeier, K Hoshina, D Hubert, W Huelsnitz, J-P Hülss, PO Hulth, K Hultqvist, S Hussain, A Ishihara, J Jacobsen, GS Japaridze, H Johansson, JM Joseph, K-H Kampert, A Kappes, T Karg, A Karle, JL Kelley, N Kemming, P Kenny, J Kiryluk, F Kislat, SR Klein, J-H Köhne, G Kohnen, H Kolanoski, L Köpke, S Kopper, DJ Koskinen, M Kowalski, T Kowarik, M Krasberg, T Krings, G Kroll, K Kuehn, T Kuwabara, M Labare, S Lafebre, K Laihem, H Landsman, MJ Larson, R Lauer, R Lehmann, J Lünemann, J Madsen, P Majumdar, A Marotta, R Maruyama, K Mase, HS Matis, K Meagher, M Merck, P Mészáros, T Meures, E Middell, N Milke, J Miller, T Montaruli, R Morse, SM Movit, R Nahnhauer, JW Nam, U Naumann, P Niessen, DR Nygren, S Odrowski, A Olivas, M Olivo, A O'Murchadha, M Ono, S Panknin, L Paul, C Pérez de los Heros, J Petrovic, A Piegsa, D Pieloth, R Porrata, J Posselt, PB Price, M Prikockis, GT Przybylski, K Rawlins, P Redl, E Resconi, W Rhode, M Ribordy, A Rizzo, JP Rodrigues, P Roth, F Rothmaier, C Rott, T Ruhe, D Rutledge, B Ruzybayev, D Ryckbosch, H-G Sander, M Santander, S Sarkar, K Schatto, T Schmidt, A Schoenwald, A Schukraft, A Schultes, O Schulz, M Schunck, D Seckel, B Semburg, SH Seo, Y Sestayo, S Seunarine, A Silvestri, A Slipak, GM Spiczak, C Spiering, M Stamatikos, T Stanev, G Stephens, T Stezelberger, RG Stokstad, S Stoyanov, EA Strahler, T Straszheim, GW Sullivan, Q Swillens, H Taavola, I Taboada, A Tamburro, O Tarasova, A Tepe, S Ter-Antonyan, S Tilav, PA Toale, S Toscano, D Tosi, D Turčan, N van Eijndhoven, J Vandenbroucke, A Van Overloop, J van Santen, M Vehring, M Voge, B Voigt, C Walck, T Waldenmaier, M Wallraff, M Walter, C Weaver, C Wendt, S Westerhoff, N Whitehorn, K Wiebe, CH Wiebusch, DR Williams, R Wischnewski, H Wissing, M Wolf, K Woschnagg, C Xu, XW Xu, G Yodh, S Yoshida, P Zarzhitsky, IceCube Collaboration

Abstract:

IceCube has become the first neutrino telescope with a sensitivity below the TeV neutrino flux predicted from gamma-ray bursts if gamma-ray bursts are responsible for the observed cosmic-ray flux above 10(18)  eV. Two separate analyses using the half-complete IceCube detector, one a dedicated search for neutrinos from pγ interactions in the prompt phase of the gamma-ray burst fireball and the other a generic search for any neutrino emission from these sources over a wide range of energies and emission times, produced no evidence for neutrino emission, excluding prevailing models at 90% confidence.
More details from the publisher
More details
Details from ArXiV

Dark matter profiles and annihilation in dwarf spheroidal galaxies: prospectives for present and future gamma-ray observatories - I. The classical dSphs

ArXiv 1104.0412 (2011)

Authors:

A Charbonnier, C Combet, M Daniel, S Funk, JA Hinton, D Maurin, C Power, JI Read, S Sarkar, MG Walker, MI Wilkinson

Abstract:

Due to their large dynamical mass-to-light ratios, dwarf spheroidal galaxies (dSphs) are promising targets for the indirect detection of dark matter (DM) in gamma-rays. We examine their detectability by present and future gamma-ray observatories. The key innovative features of our analysis are: (i) We take into account the angular size of the dSphs; while nearby objects have higher gamma ray flux, their larger angular extent can make them less attractive targets for background-dominated instruments. (ii) We derive DM profiles and the astrophysical J-factor (which parameterises the expected gamma-ray flux, independently of the choice of DM particle model) for the classical dSphs directly from photometric and kinematic data. We assume very little about the DM profile, modelling this as a smooth split-power law distribution, with and without sub-clumps. (iii) We use a Markov Chain Monte Carlo (MCMC) technique to marginalise over unknown parameters and determine the sensitivity of our derived J-factors to both model and measurement uncertainties. (iv) We use simulated DM profiles to demonstrate that our J-factor determinations recover the correct solution within our quoted uncertainties. Our key findings are: (i) Sub-clumps in the dSphs do not usefully boost the signal; (ii) The sensitivity of atmospheric Cherenkov telescopes to dSphs within 20 kpc with cored halos can be up to ~50 times worse than when estimated assuming them to be point-like. Even for the satellite-borne Fermi-LAT the sensitivity is significantly degraded on the relevant angular scales for long exposures, hence it is vital to consider the angular extent of the dSphs when selecting targets; (iii) No DM profile has been ruled out by current data, but using a prior on the inner dark matter cusp slope 0<=gamma<=1 provides J-factor estimates accurate to a factor of a few if an appropriate angular scale [abridged]
Details from ArXiV
More details from the publisher