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High-energy gamma rays and the large-scale distribution of gas and cosmic rays

Published online by Cambridge University Press:  04 August 2017

W. Hermsen  and
J.B.G.M. Bloemen
W. Hermsen
Affiliation:
Cosmic Ray Working Group, Huygens Laboratorium, Leiden, The Netherlands
J.B.G.M. Bloemen
Affiliation:
Sterrewacht and Cosmic Ray Working Group, Huygens Laboratorium, Leiden, The Netherlands

Extract

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The COS-B gamma-ray survey is compared with 12CO and HI surveys in a region containing the Orion complex and in the outer Galaxy. The observed gamma-ray intensities in the Orion region (100 MeV<E<5 GeV) can be ascribed to the interaction of uniformly distributed cosmic rays with the interstellar gas. Calibration of the ratio between H2 column-density and integrated CO line intensity resulted in the value: (3.0±0.7)x102 0 molecules cm-2K -1km -1s. In the outer Galaxy HI column-density maps in three galacto-centric distance ranges are used in combination with COS-B gamma-ray data to determine the radial distribution of the gamma-ray emissivity. A steep negative gradient of the emissivity for the 70 MeV-150 MeV range and an approximately constant (within ~20%) emissivity for the 300 MeV-5 GeV range is found. The result is interpreted as a strong decrease in the cosmic-ray electron density and a near constancy of the nuclear component.

Type
PART II: COMPOSITION, STRUCTURE AND KINEMATICS
Information
Symposium - International Astronomical Union , Volume 106: The Milky Way Galaxy , 1985 , pp. 213 - 218
Copyright
Copyright © Reidel 1985 

References

Blitz, L., Fich, M., and Stark, A.A.: 1980, in Interstellar Molecules , ed. Andrew, B., Reidel, Dordrecht, p.213 CrossRefGoogle Scholar
Bloemen, J.B.G.M., Blitz, L., and Hermsen, W.: 1984, Ap.J., in press Google Scholar
Bloemen, J.B.G.M., et al.: 1984a, Astron. Astrophys., submitted Google Scholar
Bloemen, J.B.G.M., et al.: 1984b, Astron. Astrophys., in prep Google Scholar
Caraveo, P.A., et al.: 1980, Astron. Astrophys., 91, L3 Google Scholar
Caraveo, P.A., et al.: 1981, Proc. 17th Int. Cosmic Ray Conf. , Paris, 1, p.139 Google Scholar
Heiles, C., and Habing, H.J.: 1974, Astron. Astrophys. Suppl. 14, p.1 Google Scholar
Henderson, A.P., Jackson, P.D., and Kerr, F.J.: 1982, Ap. J. 263, p.116 CrossRefGoogle Scholar
Hermsen, W.: 1980, Ph. D. Thesis, University of Leiden, The Netherlands Google Scholar
Hermsen, W. and Bloemen, J.B.G.M.: 1983, in Southern Galactic Surveys , eds. Israel, F.P. and Burton, W.B., Reidel, Dordrecht, p.65 CrossRefGoogle Scholar
Kulkarni, S.R., Blitz, L., and Heiles, C.: 1982, Ap. J. Letters 259, L63 CrossRefGoogle Scholar
Lebrun, et al.: 1982, Astron. Astrophys. 107, p.390 Google Scholar
Lebrun, F., and Paul, J.A.: 1983, Ap. J. 266, p.276 CrossRefGoogle Scholar
Lequeux, J.: 1981, Comments on Astrophysics, 9, p.117 Google Scholar
Mayer-Hasselwander, H.A., et al.: 1982, Astron. Astrophys. 105, p.164 Google Scholar
Phillipps, S., et al.: 1981, Astron. Astrophys. 98, p.286 Google Scholar
Stephens, S.A., and Badwahr, G.D.: 1981, Astrophys. and Space Science 76, p.213 CrossRefGoogle Scholar
Strong, A.W., et al.: 1982, Astron. Astrophys. 115, p.404 Google Scholar
Weaver, H., and Williams, D.R.W.: 1973, Astron. Astrophys. Suppl. 8, p.1 Google Scholar
Webber, W.R., Simpson, G.A., and Cane, H.V.: 1980, Ap. J. 236, p.448 CrossRefGoogle Scholar