NONTHERMAL RADIO EMISSION FROM SNR IN THE PRE-SEDOV STAGE OF EVOLUTION : WEAK MAGNETIC APPROXIMATION

초기 초신성 잔해의 비열적 전파복사 : 약한 자기장 근사

  • 최승언 (서울대학교, 사범대학, 지구과학교육과) ;
  • 정현철 (서울대학교, 사범대학, 지구과학교육과)
  • Published : 1995.12.31

Abstract

It has been recognized that the morphologies of the SNRs from the radio observation are "barrel shaped". To interpret the mechanism of the radiation and the physical state of the environments, we have analytically calculated the dynamical structure of the interacting region in the case where the ejectum has a steep power-law density profile($\rho{\sim}r^{-n}$) and the ambient medium has a shallow power-law density profile($\rho{\sim}r^{-s}$), assuming that the cosmic rays are isotropically accelerated in the shock wave and the magnetic fields are very weak. The calculated synchrotron radio maps show that the emission from the equator is intense and the emissions from the central and polar regions are less intense. Also the thicknesses of the shell are strongly dependent on s and weakly on n. The azimuthal intensity ratio $\alpha$ increases as the efficiency of the cosmic ray acceleration increases and s decreases. We compared the results with the morphology of the SNR A. D. 1006(type I SNR). It does agree with the case of s = 0, w = 0.3 - 0.5. This value for w is consistent with the results by Eichler(1979). It provides us the evidence of the cosmic ray acceleration in the shock wave.

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