Transcript ppt
SNR-MC interaction and x-ray gamma-ray signature Slane et al. arXiv: 1406.4364 speaker: 高原 §Introduction • Supernova, especially Core-Collapse in giant molecular clouds • SNR-MC interaction impact the evolution • X-ray: evolution • Gamma-ray: energetic particles acceleration 2 §Observational signatures • A large persentage of the few hundreds of SNR 1. morphological traces along the periphery 2. broadenings, wings, asymmetries in the molecular line spectra (Frail and Mitchell 1998) 3. high ratios between lines of different excitation state (Seta et al. 1998) 4. detection of near infrared H2 or [FeII] lines 5. peculiar infrared colors (Reach et al. 2006) 6. the presence of OH (1720MHz) masers 3 HI emission • explore the history of the precursor star • estimate the gas density of the medium where the blast wave expands • shells and super-shells (Park et al. 2013), • and hints for nature of "dark" gamma-ray sources (eg. Gabanyi et al. 2013) 4 About CO observation • Herschel Space Observatory revealed that the molecular gas can be hugely underestimated with traditional methods (Pineda et al. 2013) • [CII] 158um: envelope of evolved clouds SNR-MC can be used to determine the distance 5 Masers • • • • • 1720 MHz, C-type shock 50--125 K, 103-5 cm-3, 1016-17 cm-2 ~24 SNRs, summarized by Brogan et al. 2013 independent estimate for kinematic distances directly observing the magnetic field strength using Zeeman effect • Where dose OH come from (Wardle and YusefZadeh 2002) – x-ray or CR? 6 Radiative shocks • optical and fine-structure in IR • [OIII]... • [FeII] 1.257 um, 1.644 um Kokusho et al. 2013 (IC443) • Bykov et al. 2008, 24 um likely dominated by [Fe II] 26um rather than heated dust 7 §X-rays from SNR-MC • dense MC distort the morphology • the high density lead to rapid ionization • drive a strong reverse shock into the ejecta 8 X-ray morphology • dense cloud impede the shock • absorption 9 §Thermal composite (MM) • Thermal conduction • Cloudlet evaporation – evaportion time scale • MM SNR – ionizated stats – SNR-MC interaction--statistics? – aboundances 10 §Gamma-rays from SNR-MC • hadronic • leptonic 11 §Gamma-rays from SNR-MC • density from gamma-ray exceeds that from x-ray – x-ray from inter-clump materials; gamma-ray from dense clumps – escaping CRs interacting with external MCs 12 Kes 41