高能暂现源 · 每日文献综述

Ultra-high-energy neutrinos and cosmic rays are excellent probes of astroparticle physics phenomena. For astroparticle physics analyses, robust and accurate reconstruction of signal parameters such as arrival direction and energy is essential. Radio detection is an established detector concept explored by many observatories; however, current reconstruction methods ignore bin-to-bin noise correlations, which limits reconstruction resolution and, so far, has prevented calculations of event-by-event uncertainties. In this work, we present a likelihood description of neutrino or cosmic-ray signals in radio detectors with correlated noise, as present in all neutrino and cosmic-ray radio detectors. We demonstrate, with simulation studies of both neutrinos and cosmic-ray radio signals, that signal parameters such as energy and direction, including event-by-event uncertainties with correct coverage, can be obtained. This method reduces reconstruction uncertainties and biases compared to previous approaches. Additionally, the Likelihood can be used for event selection and enables differentiable end-to-end detector optimization. The reconstruction code is available through the open-source software NuRadioReco.

The study presents a confirmation of six quadruples with two sets of eclipses that have the 2+2 architecture. These so-called doubly eclipsing systems still present a quite rare group of stars. We collected all available photometric data and carried out a detailed analysis of them. In addition to the precise TESS photometry used to model the light curves for both inner eclipsing binaries, photometric survey data were also used, and more than 100 nights of our own dedicated observations were carried out. These were mainly used for the detection of the long-term evolution of orbital periods. Thanks to these data, we were able to derive the mutual orbits of the inner doubles via eclipse timing variations. The systems studied are: CzeV1254 (periods 0.715348 d + 0.362593 d, mutual period 15.6 yr); ASASSN-V J070838.27-171952.9 (4.300490 d + 3.767235 d, 4 yr); ASASSN-V J091951.17-593306.9 (2.668674 d + 14.342218 d, 0.95 yr); WISE J100820.07-731554.0 (0.368315 d + 7.945339 d, 3.8 yr); ASASSN-V J143536.01-721459.4 (7.353842 d + 6.368567 d, 27.4 yr); and Corot 310284765 (1.875418 d + 2.371126 d, 22.6 yr). Some of the binaries show significantly eccentric orbits. We also estimated their apsidal motion periods. With our six new systems, the number of confirmed orbits of 2+2 quadruples has been increased to 64 in total.