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Formation of giant H II regions following supernova explosionsThe principal optical properties of type I supernovae are summarized. These include the light curve and the spectrum. The spectra consist of broad bands with very little continuum. According to the theory presented, the observed light is principally fluorescence, excited in the medium surrounding the supernova by ultraviolet radiation originating from the explosion. It is proposed that the spectrum that impinges on the fluorescent medium while emission is taking place must fall abruptly across the Lyman edge of He II. Such a filtering action is plausibly provided by a much denser internal region, rich in helium, immediately surrounding the exploding object. This will form a Stromgren sphere during the time the intense UV pulse is passing through it. The dense region also slows down the photons below the edge by Thomson scattering, thereby spreading out the UV pulse in time. Various proposed mechanisms for the production of ionization in the Gum nebula are discussed.
Document ID
19720004105
Document Type
Conference Paper
Authors
Sartori, L. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Date Acquired
August 6, 2013
Publication Date
September 1, 1971
Publication Information
Publication: NASA. Goddard Space Flight Center The Gum Nebula and Related Probl.
Subject Category
SPACE SCIENCES
Funding Number(s)
CONTRACT_GRANT: NSF GP-11453
CONTRACT_GRANT: NGL-22-009-019
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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