Bibcode
Plüschke, S.; Cerviño, M.; Diehl, R.; Kretschmer, K.; Hartmann, D. H.; Knödlseder, J.
Bibliographical reference
New Astronomy Reviews, Volume 46, Issue 8-10, p. 535-539.
Advertised on:
7
2002
Journal
Citations
18
Refereed citations
15
Description
The COMPTEL observations of the galactic 1.809 MeV emission attributed
to the radioactive decay of 26Al have confirmed the diffuse
nature of this interstellar emission line. One of the most significant
features of the reconstructed intensity pattern is a flux enhancement
towards Cygnus. This region is fairly young and contains a wealth of
massive stars, most of them grouped in the Cygnus OB associations.
Multi-frequency model fitting strongly supports the hypothesis of
massive stars and their descendent supernovae being the dominant sources
of interstellar 26Al as observed by COMPTEL. Massive stars
and supernovae are known to impart a large amount of kinetic energy into
their surroundings causing shock regions and large cavities in the ISM.
In addition, a significant fraction of the electro-magnetic radiation of
these stars is emitted in the EUV regime leading to photoionisation of
the surrounding medium. We applied a population synthesis model in
combination with an 1D model of expanding superbubbles to the Cygnus OB
associations. Besides the expected 1.809 MeV flux and the γ-ray
line intensity due to interstellar 60Fe we compute the sizes
and expansion parameters of the expected HI-structures and the free-free
emission intensities due to the photoionizing radiation from massive
stars within this region of the sky. We discuss our present
understanding of the Cygnus region with respect to the massive star
census. Our model assigns about 70% of the 1.809 MeV intensity to six
known OB associations, about 20% to known isolated sources and roughly
10% to an unknown diffuse component.