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