Observation of Terrestrial gamma-ray flashes in the RELEC space experiment on the <Emphasis Type="Italic">Vernov</Emphasis> satellite

The RELEС scientific payload of the Vernov satellite launched on July 8, 2014 includes the DRGE spectrometer of gamma-rays and electrons. This instrument comprises a set of scintillator phoswich-detectors, including four identical X-ray and gamma-ray detector with an energy range of 10 kev to 3 MeV with a total area of ~500 cm² directed to the atmosphere, as well as an electron spectrometer containing three mutually orthogonal detector units with a geometric factor of ~2 cm² sr. The aim of a space experiment with the DRGE instrument is the study of fast phenomena, in particular Terrestrial gamma-ray flashes (TGF) and magnetospheric electron precipitation. In this regard, the instrument provides the transmission of both monitoring data with a time resolution of 1 s, and data in the event-by-event mode, with a recording of the time of detection of each gamma quantum or electron to an accuracy of ~15 μs. This makes it possible to not only conduct a detailed analysis of the variability in the gamma-ray range, but also compare the time profiles with the results of measurements with other RELEC instruments (the detector of optical and ultraviolet flares, radio-frequency and low-frequency analyzers of electromagnetic field parameters), as well as with the data of ground-based facility for thunderstorm activity. This paper presents the first catalog of Terrestrial gamma-ray flashes. The criterion for selecting flashes required in order to detect no less than 5 hard quanta in 1 ms by at least two independent detectors. The TGFs included in the catalog have a typical duration of ~400 μs, during which 10–40 gamma-ray quanta were detected. The time profiles, spectral parameters, and geographic position, as well as a result of a comparison with the output data of other Vernov instruments, are presented for each of candidates. The candidate for Terrestrial gamma-ray flashes detected in the near-polar region over Antarctica is discussed.     

Analysis of Fast Variations in Electron Fluxes in the Gap Region Using the Normalized Range Method Based on Measurement Data on the SiriusSat-1 Satellite

Cosmic Research - The use of the normalized range method for an analysis of the fast variability of electron fluxes in near-Earth space is proposed. This method makes it possible to conclude...     

Experiment on the <Emphasis Type="Italic">Vernov</Emphasis> satellite: Transient energetic processes in the Earth’s atmosphere and magnetosphere. Part I: Description of the experiment

The program of physical studies on the Vernov satellite launched on July 8, 2014 into a polar (640 × 830 km) solar-synchronous orbit with an inclination of 98.4° is presented. We described the complex of scientific equipment on this satellite in detail, including multidirectional gamma-ray detectors, electron spectrometers, red and ultra-violet detectors, and wave probes. The experiment on the Vernov satellite is mainly aimed at a comprehensive study of the processes of generation of transient phenomena in the optical and gamma-ray ranges in the Earth’s atmosphere (such as high-altitude breakdown on runaway relativistic electrons), the study of the action on the atmosphere of electrons precipitated from the radiation belts, and low- and high-frequency electromagnetic waves of both space and atmospheric origin.     

Tests for coalescing binary neutron stars as cosmological origin of gamma-ray bursts

Theoretical logN-logS distributions and (V/V _max) tests of gamma-ray bursts in the model of coalescence of neutron star (NS+NS) and/or NS+black hole (NS+BH) binaries are calculated for a flat Universe (=1) with different values of the cosmological constant and under various assumptions about the star formation history. The observed logN-logS distribution and value of (V/V _max)=0.33 for 411 bursts with knownC _max/C _lim from the 2d BATSE catalogue are best fitted with a model for which = 0.2 and primary star formation occurs at redshiftsz5–6.     

Experiment on the <Emphasis Type="Italic">Vernov</Emphasis> satellite: Transient energetic processes in the Earth’s atmosphere and magnetosphere. Part II. First results

We present the first experimental results on the observation of optical transients, gamma-ray bursts, relativistic electrons, and electromagnetic waves obtained during the experiment with the RELEC complex of scientific equipment on the Vernov satellite.