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1.
Acceleration of iron ions by a spherical shock wave moving through non-homogeneous solar corona is considered. The energy dependence of the mean charge of iron,
Fe(E), is determined by the characteristic acceleration time, T
a, trapping time, T
tr, and time for charge changes, T
q. The latter varies along with plasma number density during the propagation of the shock wave in the corona. Our calculations have demonstrated that adiabatic energy changes, Coulomb losses and shock broadening do not sufficiently influence the dependence
Fe(E). According to our estimations, the photoionizing processes can scarcely affect the ionic states of accelerated iron, except probably for the most powerful X10 class events. 相似文献
2.
A. K. Pavlov A. V. Blinov G. I. Vasil’ev M. A. Vdovina A. N. Konstantinov V. M. Ostryakov 《Astronomy Letters》2014,40(10):640-647
The production of the cosmogenic radionuclides 14C, 10Be, and 36Cl in the Earth’s atmosphere under the action of powerful impulsive proton and gamma-ray events (superpowerful solar flares and Galactic gamma-ray bursts) is considered. The possible “isotopic footprint” in natural archives (the concentrations of these isotopes in dated polar ice cores and annual tree rings) has been calculated by taking into account geophysical processes. The results obtained have been applied to analyzing the anomalous increase in the concentration of radiocarbon measured in tree rings dated 774–775 AD. Arguments for the fact that the most likely cause of this increase is the high-energy emission from a Galactic gamma-ray burst are adduced. 相似文献
3.
Vasil’ev G. I. Konstantinov A. N. Kudryavtsev I. V. Ogurtsov M. G. Ostryakov V. M. Pavlov A. K. Frolov D. A. 《Geomagnetism and Aeronomy》2019,59(8):1075-1080
Geomagnetism and Aeronomy - The causes of a sharp increase in the radiocarbon content in the Earth’s atmosphere for periods with abnormally low solar modulation of galactic cosmic rays (GCRs)... 相似文献
4.
5.
The formation of the energy spectra of heavy ions at the front of a parallel shock is considered taking into account ionization and recombination during the acceleration. An analytic solution for ions with three possible charge states is obtained and applied to the acceleration of the anomalous cosmic-ray component at the boundary of the heliosphere. In addition, a more general numerical model for such acceleration at a spherical shock front is developed and used to obtain the energy dependence of the mean charges for C, N, O, Ne, Si, S, Ar, and Fe ions. The model implies that highly excited ions begin to dominate over ions with low charges at energies above 1 MeV/nucleon, in agreement with observational data. 相似文献
6.
A possibility for gamma-ray bursts to arise due to thermonuclear flashes in the surface layers of accreting neutron stars is discussed. The principal difference of the sources of gamma-ray bursts from bursters is supposed to result from the existence of strong magnetic fields (1012–1013G) on the neutron star surface. It is shown that the thermonuclear energy released may be rapidly and effectively transported to the outer layers by MHD waves (in particular, by Alfvén waves). A very short growth time and rapid variations of some gamma-ray bursts may be easily explained in this case. 相似文献
7.
The results of numerical simulation of stochastic acceleration of the heavy ions (3He, 4He, 16O, and 56Fe) are presented for the impulsive solar event of October 5, 2002. The energy spectra of the aforementioned particles have
peculiarities (depressions) in the low-energy region (≤1 MeV nucleon−1). Coulomb losses in the flare plasma and adiabatic losses during interplanetary propagation are considered in the study as
possible causes of such peculiarities. 相似文献
8.
G. I. Vasil’ev V. M. Ostryakov A. K. Pavlov M. E. Chakchurina 《Geomagnetism and Aeronomy》2017,57(8):968-972
The nuclear interactions of solar-flare-accelerated protons and ions with the solar atmosphere and the deeper layers of the Sun lead to the formation of several stable and radioactive isotopes. This article examines the GEANT4 depth profiles of 2H, 3H, 3He, 6Li, 7Li, 10Be, and 14C. When accelerated particles pass through a layer of 0.1–2 g cm–2, 6Li, 7Li, 10Be, and 14C isotopes form in sufficient amounts to explain their anomalous abundances in lunar soil samples. It is assumed that they escape into interplanetary space with coronal mass ejections immediately after the flare. 相似文献
9.
Analyzing the average over a year (a) and over a month (b) of Wolf numbers and radiocarbon data (c), we have obtained the dimensions d of the solar attractor which are: 3.3 (a), 4.3 (b), 4.7 (c). During the Maunder minimum such a dimension turns out to be significantly higher: 8.0 (c); whereas during the period of a phase catastrophe (1792–1828) Wolf numbers averaged over a month yield d = 3.0 (b). We have also investigated the sensitivity of our inferences to the number of available experimental points. Positive values of the Kolmogorov entropy and first Lyapunov exponent explicitly show the stochastic behaviour of the Sun. 相似文献
10.
A. K. Pavlov A. V. Blinov G. I. Vasilyev M. A. Vdovina P. A. Volkov A. N. Konstantinov V. M. Ostryakov 《Astronomy Letters》2013,39(9):571-577
An explanation is offered for the impulsive increase in the concentration of cosmogenic radiocarbon in annual tree rings (Δ14C ～ 12‰) from AD ?775. A possible cause of such an increase could be the high-energy emission from a Galactic gamma-ray burst. It is shown that such an event should not lead to an increase in the total production of 10Be in the atmosphere, as distinct from the effect of cosmic-ray fluxes on the atmosphere. At the same time, the production of an appreciable amount of 36Cl, which can be detected in Greenland and Antarctica ice samples of the corresponding age, should be expected. This allows the effects caused by a gamma-ray burst and anomalously powerful proton events to be distinguished. 相似文献