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تسجيل مستخدم جديدSearch for single sources of ultra high energy cosmic rays on the sky
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In this paper, we suggest a new way to identify single bright sources of Ultra High Energy Cosmic Rays (UHECR) on the sky, on top of background. We look for doublets of events at the highest energies, E > 6 x 10^19 eV, and identify low energy tails, which are deflected by the Galactic Magnetic Field (GMF). For the sources which are detected, we can recover their angular positions on the sky within one degree from the real ones in 68% of cases. The reconstruction of the deflection power of the regular GMF is strongly affected by the value of the turbulent GMF. For typical values of 4 microG near the Earth, one can reconstruct the deflection power with 25% precision in 68% of cases.
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The IceCube Neutrino Observatory has recently found compelling evidence for a particular blazar producing high-energy neutrinos and $mathrm{PeV}$ cosmic rays, however the sources of cosmic rays above several $mathrm{EeV}$ remain unidentified. It is b
elieved that the same environments that accelerate ultra-high-energy cosmic rays (UHECRs) also produce high-energy neutrinos via hadronic interactions of lower-energy cosmic rays. Two out of three joint analyses of the IceCube Neutrino Observatory, the Pierre Auger Observatory and the Telescope Array yielded hints for a possible directional correlation of high-energy neutrinos and UHECRs. These hints however became less significant with more data. Recently, an improved analysis with an approach complementary to the other analyses has been developed. This analysis searches for neutrino point sources in the vicinity of UHECRs with search windows estimated from deflections by galactic magnetic fields. We present this new analysis method for searching common hadronic sources, additionally including neutrino data measured by ANTARES in order to increase the sensitivity to possible correlations in the Southern Hemisphere.
91 -
A. Barbano (for the IceCube Collaboration
, the Pierre Augern Collaboration
, the Telescope Array Collaboration
2020
The sources of ultra-high energy cosmic rays (UHECRs) are still one of the main open questions in high-energy astrophysics. If UHECRs are accelerated in astrophysical sources, they are expected to produce high-energy photons and neutrinos due to the
interaction with the surrounding astrophysical medium or ambient radiation. In particular, neutrinos are powerful probes for the investigation of the region of production and acceleration of UHECRs since they are not sensitive to magnetic deflections nor to interactions with the interstellar medium. The results of three different analyses that correlate the very high-energy neutrino candidates detected by IceCube and ANTARES and the highest-energy cosmic rays measured by the Pierre Auger Observatory and the Telescope Array will be discussed. The first two analyses use a sample of high-energy neutrinos from IceCube and ANTARES selected to have a significant probability to be of astrophysical origin. The first analysis cross-correlates the arrival directions of these selected neutrino events and UHECRs. The second one is a stacked likelihood analysis assuming as stacked sources the high-energy neutrino directions and looking for excesses in the UHECR data set around the directions of the neutrino candidates. The third analysis instead uses a larger sample of neutrinos selected to look for neutrino point-like sources. It consists of a likelihood method that looks for excesses in the neutrino point-source data set around the directions of the highest-energy UHECRs.
The origin of the ultra high energy cosmic rays (UHECR) with energies above E > 1017eV, is still unknown. The discovery of their sources will reveal the engines of the most energetic astrophysical accelerators in the universe. This is a written versi
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