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超新星遗迹 HB21 空间谱指数变化的一种新解释 A new explanation on spectrum-index spatial variation of SNR HB21

超新星遗迹 HB21 空间谱指数变化的一种新解释 A new explanation on spectrum-index spatial variation of SNR HB21 国家天文台 张喜镇 Zhang Xizhen N ational Astronomical Observatories, CAS. some published examples of SNR spectrum-index spatial variation Related physical concepts Some published explanations

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超新星遗迹 HB21 空间谱指数变化的一种新解释 A new explanation on spectrum-index spatial variation of SNR HB21

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  1. 超新星遗迹HB21空间谱指数变化的一种新解释 A new explanation on spectrum-index spatial variation of SNR HB21 国家天文台 张喜镇 Zhang Xizhen National Astronomical Observatories, CAS

  2. some published examples of SNR spectrum-index spatial variation Related physical concepts Some published explanations The new explanation Further study and observation SNR 辐射谱空间变化的发现、已发表的重要事例 SNR 辐射谱的有关物理问题 目前发表的解释 本工作介绍 待深入研究的问题

  3. SNR IC443 Green, D.A. 1986, MNRAS

  4. SNR Cygnus Loop 8663-2675 Uyaniker et al. 2004

  5. SNR G78.2+2.1 密云米波综合孔径的超新星遗迹观测研究是国际合作银道面巡天的成员 本文是使用国内资料研究结果被超新星遗迹总表引用的第一篇文章 ZHANG at al. AA 1997

  6. Zhang et al. 2002,ApSS 232，408，1420，2675，4750 MHZ DATA

  7. Some possible explanations of SNR spectrum-index variation: thermal and non-thermal mixing in projection self absorption at low frequency interaction with surrounding gas electron energy variations magnetic field distribution SNR谱指数变化的几种常见可能解释： 热和非热辐射投影性混淆 低频自吸收 与环境的相互作用 电子能谱的变化（辐射损耗，演化） 磁场分布 In order to have spectral changes with position, physical conditions must change with position --Leahy et al. 1998 引起谱指数空间变化的原因一定是能随空间变化的物理条件的变化

  8. Related physical concepts 同步加速辐射synchrotron radiation: 相对论性电子+磁场 relativistic electron + magnetic field 单粒子各向同性辐射功率single particle isotropy radiating density： P=1.1×10-15β2γ2B2 电子系集体的同步加速辐射功率 electron groupsynchrotron radiation ： j(υ)=∫Nγ. Γ-2d γdΩdp / d υ 电子系集体的同步加速辐射谱 electron group synchrotron spectrum: j(υ) ∝ υ-q

  9. SNR HB21 spectrum-index spatial variation: thermal and non-thermal mixing in projection, self absorption at low frequency, interaction with surrounding gas, magnetic field distribution,… 超新星遗迹HB21的谱指数变化： 热和非热辐射投影性混淆，低频自吸收，与环境的相互作用，磁场分布,... • thermal and non-thermal mixing in projection • 热和非热辐射投影性混淆 Cyg X 天区在5000 MHz 的图象. 由于热辐射的混淆，SNR G78.2+2.1很难被发现 同一天区在232 MHz 的图象. SNR G78.2+2.1清晰可见

  10. Temperature spectral index:β(average)=2.3, β(thermal)=2.5 => β(non-thermal=2.1) Xray/hb21

  11. 2. self absorption at low frequency, interaction with surrounding gas 低频自吸收，与环境的相互作用

  12. New 6 cm polarization data Zhang et al 2002 3. magnetic field distribution 磁场分布

  13. Summary: 决定SNR 谱指数空间变化的因素很多，定量分析有一定难度。 用磁场位型来分析谱指数空间变化，这可能是第一次。 HB21 确是一个很好的例子。说明6 CM 偏振数据在这方面研究，也是有价值的 SNR spectral index spatial variation depends multi-physical condition which are function of position. Some condition is not easy to do quantitative analysis. But the HB21 show a quite good analysis with the new 6 cm polarization data.

  14. New 6 cm polarization data SNR Cygnus Loop 8663-2675 Uyaniker et al. 2004

  15. 谢谢

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