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小组讨论会发言

小组讨论会发言. 超新星遗迹中的分子壳层. 陈阳 on behalves of 苏扬、周鑫、杨戟、具本哲. 2008 － 11 － 13. 为什么要研究 SNRs  MCs. Molecular gas takes up 1/2 mass of ISM Most core-collapse SNe are located close to GMCs --- their birth places (e.g. Huang & Thaddeus 1986)

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小组讨论会发言

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  1. 小组讨论会发言 超新星遗迹中的分子壳层 陈阳on behalves of苏扬、周鑫、杨戟、具本哲 2008－11－13

  2. 为什么要研究SNRs  MCs • Molecular gas takes up 1/2 mass of ISM • Most core-collapse SNe are located close to GMCs --- their birth places (e.g. Huang & Thaddeus 1986) •  2/3 among 270 Galactic SNRs estimated to have been interacted with MCs; only 20 are confirmed (Reynoso & Mangum 2000) 对分子云的物理作用： • 压缩、加热、驱动气体 • 激发、电离乃至离解分子 • 往往在小比例电离分子云内以连续型（C 型）激波推进，伴随着双极扩散等重要物理 过程 • 高温、高密环境还影响气体的化学演化，伴随着本不可能的分子谱线的发射（如OH 脉泽） • 可能引发湍动和恒星形成 (e.g., Woodward 1976) • 特别重要：激波与云p-p碰撞  0  2， TeV  射线源，目前热点问题之一 SN2006gy in NGC1260 Observations of MCs  SNRs : CO, OH, HCO+… 开发德令哈 ！开发K(C)OSMA !

  3. CO towards SNRs CO,13CO (J=1-0) broadening,intensified A survey of 26 Galactic SNRs, ~half are detected in CO line (Huang & Thaddeus 1986). Pioneer works: W44 (Wootten 1977) C: no CO W28 (Wootten 1981) IC443 (DeNoyer 1979)

  4. OH (1720MHz) towards SNRs Survey: Among 260 Galactic SNRs, 33 SNRs are detected in OH 1720MHz line (Green et al. 1997) Pioneer IC443 (DeNoyer 1979)

  5. OH (1720MHz) Masers & SNRs Especially, 19 Galactic SNRs are accompanied by OH 1720 MHz masers (Green et al. 1997)! First detection (Goss & Robinson 1968) Theory (Green,A.J. 2002; Wardle & Yusef-Zadeh 2002)) • Suggested mechanisms: • e’s (produced by X-ray & CR) excite Lyman & Werner bands of H2 FUV • SNR X-ray ionization ( 1015 s1) enhances OH production (H2O + FUV OH +H, Wardle 1999; Yusef-Zadeh et al.2003), • SN C-type shocks in MCs (50-125K, 105cm3) produce OH masers (column 1016cm2) (Lockett et al. 1999) • marking interaction between SNRs & MCs

  6. 德令哈 CO、HCO+、HCN巡测、单测计划 • 与SNR位置、形态相关性，特别关注空腔（cavity）、壳层（shell）结构； • 相互作用的证据：激波作用区域分子气体的谱线轮廓、速度场结构、气体密度和激发温度的分布； • 超新星遗迹成协分子云内恒星形成的影响。

  7. Molecular shells in SNRs? W49B: C-type shock? 3C397: 13CO shell? Both suggested to be in wind-blown bubbles.

  8. Wind-bubble scenario Other examples suggested in wind bubbles N132D: hitting cavity wall (Chen et al. 03) DA530 (Landecker et al. 98) HI walls, all not yet confirmed to be with MCs ! Kes27: shock reflection (Chen et al. 08)

  9. Kes 69 • 特征： • 东南残段壳层: 射电，4.5 & 5.8 m (Spitzer) • 西北致密OH 1720 MHz脉泽，VLSR=69 km/s • 南缘延展OH 1720 MHz脉泽，VLSR=85 km/s

  10. Kes 69: CO shell 80-81 km/s 79-82 km/s 12CO 13CO HCO+ 12CO 13CO C18O Association  d = 5.2 kpc (other than 11.2 kpc) Blue-shifted broadening

  11. Kes 75 • 特征： • 中间PWN • 南面半个壳层 （radio，IR） • 南面两个X射线亮块 49-58 km/s 78-101 km/s

  12. Kes 75: 54km/s component N(H2)  1 cm2

  13. Morphological correspondence Association  d = 10.6 kpc (other than 19 or 6 kpc)

  14. Kes 75: Chandra X-ray spectra NH   cm2

  15. MC-shock interaction • radio continuum: blast wave in ICM /slowed by clouds • X-ray: hot gas (blast-heated, evaporated), ejecta • NIR: 4.5 m– shocked gas (neutrals & mol.s, not PAH) 5.8 m – shocked mol. gas (H2) / ionized (FeII) 24 m – heated dust grains / shocked H2, OH shocked molecules consistent with OH masers, HCO+ consistent with C-type shockes Kes 69Kes 75 Pressure balance: >> average cloud n(H2)~60-100 cm3 Why?

  16. Difficulties with swept-up scenario Kes 69Kes 75 Age: Energy: X-rays: vs ~ 10 km/s too small if only n0 ~ 0.1 cm3 ! Radio emission: H2 formation timescale: (1) CR acceleration needs there would have been no molecules! no new CRs (2) ambipolar diffusion timescale ta-d B field separated, old e escaped

  17. Molecular shells of wind-bubble Ring Nebula: G79.29+0.46 • Imprints of massive star evolution • Natural explanation of why the shells pre-exist & what the shells are (e.g. high n_H2) • Avoid the dynamical difficulties (e.g. high E) Rizzo et al. (08) Kes 69Kes 75 Bubble expansion velocity: similar to the velocity shift

  18. A schetch for Kes 75 N(H2)  1 cm2 N(H2)  51 cm2 NH   cm2 Kes75: -ray excess LX/L  10, 1/3 G21.50.9, 1/12 Crab Partial -ray contribution from pp  0 decay ?

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