| 1. |
- Ahrens, J., et al.
(author)
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Search for Extraterrestrial Point Sources of Neutrinos with AMANDA-II
- 2004
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 92:7, s. 711021-711025
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Journal article (peer-reviewed)abstract
- The results of a search for point sources of high energy neutrinos in the northern hemisphere were presented using AMANDA-II data collected in the year 2000. The results included the flux limits on several active-galactic-nuclei blazars, microquasars, magnetars, and other candidate neutrino sources. A search for excesses above a random background of cosmic ray induced atmospheric neutrinos and misreconstructed downgoing cosmic-rays muons, which revealed no statistically significant neutrino point sources was also presented. It was shown that AMANDA-II had achieved the sensitivity required to probe known TeV γ-ray sources such as the blazar Markarian 501 in its 1997 flaring state at a level where neutrino and γ-ray fluxes were equal.
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| 2. |
- Niessen, Peter, et al.
(author)
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Recent results from the amanda experiment
- 2003
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In: Proceedings of 38th Rencontres de Moriond on Electroweak Interactions and Unified Theories 15-22 Mar 2003. Les Arcs, France.
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Conference paper (peer-reviewed)abstract
- AMANDA (Antarctic Muon And Neutrino Detector Array) is a neutrino telescope built under the southern polar icecap and its scope is to explore the possibility to detect high energy cosmic neutrinos. This should generate insight into the powerful celestial objects where acceleration mechanisms can bring up to 10 20 eV. We describe the achievements and results from the AMANDA-B10 prototype and the preliminary results from the current AMANDA-II detector which show dramatic increase in sensitivity.
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| 3. |
- Ahrens, J., et al.
(author)
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Calibration and survey of AMANDA with the SPASE detectors
- 2004
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 522:3, s. 347-359
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Journal article (peer-reviewed)abstract
- We report on the analysis of air showers observed in coincidence by the Antarctic Muon and Neutrino detector array (AMANDA-B10) and the South Pole Air Shower Experiment (SPASE-1 and SPASE-2). We discuss the use of coincident events for calibration and survey of the deep AMANDA detector as well as the response of AMANDA to muon bundles. This analysis uses data taken during 1997 when both SPASE-1 and SPASE-2 were in operation to provide a stereo view of AMANDA. © 2003 Elsevier B.V. All rights reserved.
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| 4. |
- Ahrens, J., et al.
(author)
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Measurement of the cosmic ray composition at the knee with the SPASE-2/AMANDA-B10 detectors
- 2004
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In: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 21:6, s. 565-581
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Journal article (peer-reviewed)abstract
- The mass composition of high-energy cosmic rays at energies above 1015 eV can provide crucial information for the understanding of their origin. Air showers were measured simultaneously with the SPASE-2 air shower array and the AMANDA-B10 Cherenkov telescope at the South Pole. This combination has the advantage to sample almost all high-energy shower muons and is thus a new approach to the determination of the cosmic ray composition. The change in the cosmic ray mass composition was measured versus existing data from direct measurements at low energies. Our data show an increase of the mean log atomic mass 〈lnA〉 by about 0.8 between 500 TeV and 5 PeV. This trend of an increasing mass through the "knee" region is robust against a variety of systematic effects. © 2004 Elsevier B.V. All rights reserved.
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| 5. |
- Ahrens, J., et al.
(author)
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Limits on diffuse fluxes of high energy extraterrestrial neutrinos with the AMANDA-B10 detector
- 2003
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In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 90:25, s. 2511011-2511015
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Journal article (peer-reviewed)abstract
- A report on the limits, which could be placed on diffuse fluxes of high energy extraterrestrial neutrinos, was presented. The incorporation of neutrino oscillations was necessary for interpreting the limits in terms of the flux from a cosmological distributions of sources. The energetic accelerated environments were presented as the sources of high energy extraterrestrial neutrinos.
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| 6. |
- Ahrens, J., et al.
(author)
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Muon track reconstruction and data selection techniques in AMANDA
- 2004
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 524:1-3, s. 169-194
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Journal article (peer-reviewed)abstract
- The Antarctic Muon And Neutrino Detector Array (AMANDA) is a high-energy neutrino telescope operating at the geographic South Pole. It is a lattice of photo-multiplier tubes buried deep in the polar ice between 1500 and 2000 m. The primary goal of this detector is to discover astrophysical sources of high-energy neutrinos. A high-energy muon neutrino coming through the earth from the Northern Hemisphere can be identified by the secondary muon moving upward through the detector. The muon tracks are reconstructed with a maximum likelihood method. It models the arrival times and amplitudes of Cherenkov photons registered by the photo-multipliers. This paper describes the different methods of reconstruction, which have been successfully implemented within AMANDA. Strategies for optimizing the reconstruction performance and rejecting background are presented. For a typical analysis procedure the direction of tracks are reconstructed with about 2° accuracy. © 2004 Elsevier B.V. All rights reserved.
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| 7. |
- Ahrens, J., et al.
(author)
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Results from the AMANDA telescope
- 2003
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In: Nuclear Physics A. - : Elsevier. - 0375-9474 .- 1873-1554. ; 721, s. C545-C548
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Journal article (peer-reviewed)abstract
- We present results from the AMANDA high energy neutrino telescope located at the South Pole. They include measurements of the atmospheric neutrino flux, search for UHE point sources, and diffuse sources producing electromagnetic/hadronic showers at the detector or close to it.
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| 8. |
- Ahrens, J., et al.
(author)
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Physics and operation of the AMANDA-II high energy neutrino telescope
- 2002
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In: Proceedings of the SPIE - The International Society for Optical Engineering 2003. - : Institution of Electrical Engineers (IEE). ; , s. 79-91
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Conference paper (peer-reviewed)abstract
- This paper briefly describes the principle of operation and science goals of the AMANDA high energy neutrino telescope located at the South Pole, Antarctica. Results from an earlier phase of the telescope, called AMANDA-B10, demonstrate both reliable operation and the broad astrophysical reach of this device, which includes searches for a variety of sources of ultrahigh energy neutrinos: generic point sources, Gamma-Ray Bursts and diffuse sources. The predicted sensitivity and angular resolution of the telescope were confirmed by studies of atmospheric muon and neutrino backgrounds. We also report on the status of the analysis from AMANDA-II, a larger version with far greater capabilities. At this stage of analysis, details of the ice properties and other systematic uncertainties of the AMANDA-II telescope are under study, but we have made progress toward critical science objectives. In particular, we focus on the search for continuous emission from astrophysical point sources and the search for correlated neutrino emission from Gamma Ray Bursts detected by BATSE before decommissioning in May 2000. During the next two years, we expect to exploit the full potential of AMANDA-II with the installation of a new data acquisition system that records full waveforms from the in-ice optical sensors.
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| 9. |
- Ahrens, J., et al.
(author)
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Search for point sources of high-energy neutrinos with AMANDA
- 2003
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In: Astrophysical Journal Letters. - : Institute of Physics (IOP). - 2041-8205 .- 0004-637X .- 1538-4357. ; 583:2 I, s. 1040-1057
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Journal article (peer-reviewed)abstract
- This paper describes the search for astronomical sources of high-energy neutrinos using the AMANDA-B10 detector, an array of 302 photomultiplier tubes used for the detection of Cerenkov light from upward-traveling neutrino-induced muons, buried deep in ice at the South Pole. The absolute pointing accuracy and angular resolution were studied by using coincident events between the AMANDA detector and two independent telescopes on the surface, the GASP air Cerenkov telescope and the SPASE extensive air shower array. Using data collected from 1997 April to October (130.1 days of live time), a general survey of the northern hemisphere revealed no statistically significant excess of events from any direction. The sensitivity for a flux of muon neutrinos is based on the effective detection area for through-going muons. Averaged over the northern sky, the effective detection area exceeds 10,000 m2 for E μ ≈ 10 TeV. Neutrinos generated in the atmosphere by cosmic-ray interactions were used to verify the predicted performance of the detector. For a source with a differential energy spectrum proportional to Eν -2 and declination larger than +40°, we obtain E2(dNν/dE) ≤ 10-6 GeV cm-2 s-1 for an energy threshold of 10 GeV.
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| 10. |
- Wiebusch, C., et al.
(author)
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Results from AMANDA
- 2002
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In: Modern Physics Letters A. - : Institution of Electrical Engineers (IEE). - 0217-7323 .- 1793-6632. ; 17:31, s. 2019-2037
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Journal article (peer-reviewed)abstract
- The Antarctic Muon and Neutrino Detector Array (AMANDA) is a high-energy neutrino telescope operating at the geographic South Pole. It is a lattice of photomultiplier tubes buried deep in the polar ice. The primary goal of this detector is to discover astrophysical sources of high energy neutrinos. We describe the detector methods of operation and present results from the AMANDA-B10 prototype. We demonstrate the improved sensitivity of the current AMANDA-II detector. We conclude with an outlook to the envisioned sensitivity of the future IceCube detector.
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