Publications by authors named "D V Semikoz"
Article Synopsis
- - On October 9, 2022, LHAASO detected a significant afterglow from the gamma-ray burst 221009A, achieving record photon statistics in the TeV energy range.
- - This observation allowed researchers to test the idea of Lorentz invariance violation (LIV), which is related to faster-than-light travel predictions in some quantum gravity theories.
- - The study established that the energy scales for LIV effects are significantly higher than previously thought, with new lower limits being 10 times the Planck energy for linear effects and 6×10^{-8} times the Planck energy for quadratic effects, improving earlier constraints by 5-7 times.
In this Letter we try to search for signals generated by ultraheavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible γ rays by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of the LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter that have low fluxes of astrophysical γ-ray background while having large amount of dark matter.
View Article and Find Full Text PDFWe present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.
View Article and Find Full Text PDFIceCube Collaboration has previously reported evidence for a neutrino signal from a Seyfert galaxy NGC 1068. This may suggest that all Seyfert galaxies emit neutrinos. To test this hypothesis, we identify the best candidate neutrino sources among nearby Seyfert galaxies, based on their hard x-ray properties.
View Article and Find Full Text PDFThe diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°