Search for Sources of High-Energy Neutrons with Four Years of Data from the IceTop Detector

• Published in: The Astrophysical Journal
• Main Authors: Aartsen, M. G., Abraham, K., Ansseau, I., Grant, D., Griffith, Z., Haack, C., Ismail, A. Haj, Hallgren, A., Halzen, F., Hansen, E., Hansmann, B., Hansmann, T., Hanson, K., Anton, G., Hebecker, D., Heereman, D., Helbing, K., Hellauer, R., Hickford, S., Hignight, J., Hill, G. C., Hoffman, K. D., Hoffmann, R., Holzapfel, K., Archinger, M., Hoshina, K., Huang, F., Huber, M., Hultqvist, K., In, S., Ishihara, A., Jacobi, E., Japaridze, G. S., Jeong, M., Jero, K., Argüelles, C., Jones, B. J. P., Jurkovic, M., Kappes, A., Karg, T., Karle, A., Katz, U., Kauer, M., Keivani, A., Kelley, J. L., Kemp, J., Auffenberg, J., Kheirandish, A., Kim, M., Kintscher, T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Univ.11032 2016
• Subjects: info:eu-repo/classification/ddc/520; Antarctic; The Antarctic; South Pole; Antarc*; Ice Sheet; South pole
• Online Access: https://bib-pubdb1.desy.de/record/316261; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2016-06455%22

IceTop is an air-shower array located on the Antarctic ice sheet at the geographic South Pole. IceTop can detect an astrophysical flux of neutrons from Galactic sources as an excess of cosmic-ray air showers arriving from the source direction. Neutrons are undeflected by the Galactic magnetic field and can typically travel 10 (E/PeV) pc before decay. Two searches are performed using 4 yr of the IceTop data set to look for a statistically significant excess of events with energies above 10 PeV (10$^{16}$ eV) arriving within a small solid angle. The all-sky search method covers from −90° to approximately −50° in declination. No significant excess is found. A targeted search is also performed, looking for significant correlation with candidate sources in different target sets. This search uses a higher-energy cut (100 PeV) since most target objects lie beyond 1 kpc. The target sets include pulsars with confirmed TeV energy photon fluxes and high-mass X-ray binaries. No significant correlation is found for any target set. Flux upper limits are determined for both searches, which can constrain Galactic neutron sources and production scenarios.