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The Galaxy in Gamma-Rays from Radioactivity

The Galaxy in Gamma-Rays from Radioactivity. The ISM throughout the Galaxy 26 Al Radioactivity Positron Annihilation Roland Diehl MPE Garching , Germany. Radioactivity in Astrophysics – an Example. p n. . Al. Mg. Mg. rod/26alnucl.

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The Galaxy in Gamma-Rays from Radioactivity

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  1. The Galaxy in Gamma-Rays from Radioactivity The ISM throughout the Galaxy 26Al Radioactivity Positron Annihilation Roland Diehl MPE Garching, Germany

  2. Radioactivity in Astrophysics – an Example pn  Al Mg Mg rod/26alnucl

  3. Cosmic Radioactivities:  Production and Re-Cycling of Nuclei ISM Working Meeting, MPE, 25 Jul 2012

  4. 26Al in our Galaxy: g-ray Image and Spectrum Sco-Cen Cygnus Vela Inner Galaxy Orion Massive-Star Nucleosynthesis in the Current Galaxy: Exploiting the Message from 26Al g-rays

  5. The 26Al Gamma-Ray Line Width • Hot-Gas Kinematics throughout the Galaxy: • Account for Instrumental Line Width (~3 keV) • Extract Additional (astrophysical) Broadening  Doppler velocity • ~1.4 ±0.35 ±0.3 keVConsistent withExpectationfrom GalacticRotation (~1.35 keV) 175 ±45 km s-1

  6. Tracing Galactic Rotation towards Inner Galaxy • Clear Doppler Shifts  velocity resolution <100 km/s 26Al line Instrumental line

  7. Motion of Hot Gas in the Inner Galaxy – 26Al • Hot gas streaming away from star-forming clouds • Enhanced star formation in inner • spiral arms • Stars vs. gas/parental-cloud • motion incurs one-sided • outflow  forward in GalRotation

  8. Positrons Annihilation g-rays: Why is GC region so bright? • Annihilation g-rays are dominated by a Bright Inner-Galaxy Component • The 26Al e+ Produced in the Disk (82%) are a Minor Contribution • Annihilation g-ray Emission Presents a Puzzle: • e+ Sources ? • Propagation !! • Annihilation Knödlseder+ 2005 Weidenspointner+ 2008 Bouchet+ 2010

  9. Candidate Positron Sources • Nucleosynthesis • Accreting Binaries • Pulsars • SMBH? • Dark Matter? • Only Gamma Rays Can Tell  Locations?? Prantzos et al., RMP 83 (2011) All Spread –out in Galactic Disk!

  10. Sources of Positrons and Annihilation Sites Han 2001 Poloidal Irregular Toroidal -> Nikos Prantzos 2005 • Could e+ be transported from disk to central region of Galaxy? • Large-scale transport in halo magnetic field SPI/INTEGRAL 511 keV(Knödlseder et al. 2005)

  11. Radioactivities and ISM in the Galaxy Han 2001 Poloidal Irregular Toroidal • Radioactivity g-rays provide a different view • Emissivity Independent of complexity from environment (density, temperature) • Trace diluted ejectaat late phases = hot ISM • ISM around massive-star regions: • 26Al kinematics  Superbubble blow-out in forward directions • e+transport through chimneys & halo?

  12. Dynamics of the Interstellar Medium • The Orion Region as Test Case (Laboratory) • Mixing of SN Ejecta into Multi-Phase ISM? • Simulations: • Trace Evolution of Massive-Star Activity in Parental Cloud Fierlinger, Burkert, Diehl, et al. HI Diehl et al. 2002

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