# Radiation from collapsing stars

 1Kryvdyk, V1Taras Shevchenko National University of Kyiv, Kyiv, Ukraine Kosm. nauka tehnol. 2001, 7 ;(Suppl. 2):047-051 https://doi.org/10.15407/knit2001.02s.047 Publication Language: English Abstract:  The non-thermal emission in the magnetospheres of collapsing stars with the initial dipole magnetic fields and a certain initial energy distribution of charged particles in the magnetospheres (power-series, relativistic Maxwell, and Boltzmann distributions) are considered. When the star magnetosphere compresses under the collapse, its magnetic field increases considerably. The three factors (particle pressure, collisions between them and stellar rotation) can influence the field structure and the particles dynamics in the magnetosphere. The analysis shows, that these factors may be neglected for the magnetosphere of collapsing star. As it follows from this result, the plasma in magnetosphere is frozen in magnetic field and is collision-free. Therefore, the method of adiabatic invariant may be used to investigate the particle dynamics in magnetosphere. The vortex electric field in magnetosphere accelerates the charged particles, which generate the radiation moving in the magnetic field. The collapsing stars can be powerful sources of a non-thermal radiation produced by the interaction of charged particles with the magnetic field, as it follows from the analysis of particles dynamics and its emission in the stellar magnetosphere under collapse. The radiation flux grows with decreasing of stellar radius and frequency and it can be observed in the form of radiation burst with duration, equal to the stellar collapse time. A value of the radiation flux depends on the distance to the star, its magnetic field, and the particle spectrum in the magnetosphere. In this paper the radiation fluxes are calculated for various collapsing stars. The conclusion is made, that these fluxes can be observed by means of modern astronomical instruments.
References:
1. Beresinsky V. S., Bulanov S. V., Ginzburg V. L., et al. Asrophysics of cosmic rays, 380 p. (Nauka, Moscow, 1984) [in Russian].
2. Ginzburg V. L., Ozernoy L. M. About gravitational collapse of magnetic stars. JETP, 47, 1030—1040 (1964) [in Russian].
3. Ginzburg V. L., Syrovatskii S. I. Origin of cosmic rays, 384 p. (Izd. AN USSR, Moscow, 1963) [in Russian].
4. Gudel M., Benz A. O. Radio spectra of dMe and dKe stars. Astron. Soc. Pacif. Conf. Ser., 93, 303—305 (1996).
5. Gudel M., Benz A. O., Guiman E. F., Sthmitt J. H. M. M. Nonthermal microwave emission from F dwarfs: 71Tau, a For, and open clustermoving group membership. Astron. Soc. Pacif. Conf. Ser., 306—308 (1996).
6. Gunningam C. T., Price R. H., Moncrief V. Radiation from collapsing relativistic stars.I. Linearized odd-parity radiation. Astrophys. J., 224, 643—667 (1978).
https://doi.org/10.1086/156413
7. Gunningam C. T., Price R. H., Moncrief V. Radiation from collapsing relativistic stars. II. Linearized even-parity radiation. Astrophys. J., 230, 870—892 (1979).
https://doi.org/10.1086/157147
8. Gunningam C. T., Price R. H., Moncrief V. Radiation from collapsing relativistic stars. III. Second order perturbation of collapse with rotation. Astrophys. J., 236, 674—692 (1980).
https://doi.org/10.1086/157787
9. Linsky J. L. Steady radio emission from stars. Astron. Soc. Pacif. Conf. Ser., 93, 436—446 (1996).
10. Kryvdyk V. Collapsing stars as sources of electromagnetic radiation. Kinematika i Fizika Nebesnykh Tel, 14 (6), 475—489 (1998) [in Russian].
11. Kryvdyk V. Electromagnetic radiation from collapsing stars. I. Power-series distribution of particles in magnetospheres. Mon. Notic. Roy. Astron. Soc., 309, 593—598 (1999).
https://doi.org/10.1046/j.1365-8711.1999.02869.x
12. Moncrief V. Radiation from collapsing relativistic stars. IY. Black hole recoild. Astrophys. J., 238, 333—337 (1980).
https://doi.org/10.1086/157988
13. Utana G., Trigilio C., Catalano S. Radio emission from Algol-type binaries. I. Results of 1992-1993. VLA Survey. Astron. and Astrophys., 329, 1010—1018 (1998).
14. Van den Oort G. M. J. Non-thermal emission mechanism in stellarcoronae. Astron. Soc. Pacif. Conf. Ser., 93, 263—272 (1996).
15. Pakholchik A. G. Radio Astrophysics, 252 p. (Mir, Moscow, 1973) [in Russian].
16. Shapiro S. L., Teukolsky S. A. Black Holes, White Dwarfs, and Neutron Stars, 665 p. (Mir, Moscow, 1985) [in Russian].

17. Zeldovich J. B., Novikov I. D. Theory of gravity and stellar evolution, 494 p. (Nauka, Moscow, 1977) [in Russian].