the galaxy in gamma-rays from radioactivity
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
Roland DiehlIAU Beijing Aug 2012
The Galaxy in Gamma-Rays from Radioactivity
The ISM throughout the Galaxy
26Al RadioactivityPositron Annihilation
Roland DiehlMPE Garching, Germany
Roland DiehlIAU Beijing Aug 2012
Radioactivity in Astrophysics – an Example
rod/26alnucl
p n
Al
Mg
Mg
Roland DiehlIAU Beijing Aug 2012
ISM Working Meeting, MPE, 25 Jul 2012
Cosmic Radioactivities: Production and Re-Cycling of Nuclei
Roland Diehl 3
Roland DiehlIAU Beijing Aug 2012
Inner Galaxy
Cygnus
Orion
VelaSco-Cen
26Al in our Galaxy: -ray Image and Spectrum
Massive-Star Nucleosynthesis in the Current Galaxy:
Exploiting the Message from 26Al -rays
Roland DiehlIAU Beijing Aug 2012
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
Roland DiehlIAU Beijing Aug 2012
Tracing Galactic Rotation towards Inner Galaxy Clear Doppler Shifts velocity resolution <100 km/s
Instrumental line26Al line
Roland DiehlIAU Beijing Aug 2012
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
Roland DiehlIAU Beijing Aug 2012
Positrons Annihilation -rays: Why is GC region so bright?
Annihilation -rays are dominated by a Bright Inner-Galaxy Component
The 26Al e+ Produced in the Disk (82%) are a Minor Contribution
Annihilation -ray Emission Presents a Puzzle:
e+ Sources ? Propagation !! Annihilation
Knödlseder+ 2005
Weidenspointner+ 2008
Bouchet+ 2010
Roland DiehlIAU Beijing Aug 2012
Candidate Positron Sources Nucleosynthesis Accreting Binaries Pulsars SMBH? Dark Matter?
Only Gamma Rays Can Tell Locations??
Prantzos et al., RMP 83 (2011)
All Spread –o
ut
in Galactic D
isk!
Roland DiehlIAU Beijing Aug 2012
• Could e+ be transported from disk to central region of Galaxy?
Large-scale transport in halo magnetic field
Irregular
Toroidal
Poloidal
Han 2001
Sources of Positrons and Annihilation Sites-> Nikos Prantzos 2005
SPI/INTEGRAL 511 keV(Knödlseder et al. 2005)
Roland DiehlIAU Beijing Aug 2012
Radioactivities and ISM in the Galaxy
Radioactivity -rays provide a different viewEmissivity Independent of complexity from
environment (density, temperature) Trace diluted ejecta at late phases = hot ISM
ISM around massive-star regions: 26Al kinematics Superbubble blow-out
in forward directions
e+ transport through chimneys & halo?
IrregularToroidal
Poloidal
Han 2001
Roland DiehlIAU Beijing Aug 2012
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.
Diehl et al. 2002
HI