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| Paper: |
Coherent Spectroscopy of Supernova Remnant 1987A |
| Volume: |
413, 2nd Crisis in Cosmology Conference, CCC-2 |
| Page: |
233 |
| Authors: |
Moret-Bailly, J. |
| Abstract: |
The explanation of the shape and the spectra of SNR1987A becomes easier using coherent interactions between light and matter: Assuming that the present system is close to a Strömgren system, the relatively thin shell lying between the sphere of mainly ionised atomic hydrogen and neutral hydrogen, contains excited atomic hydrogen. It is generally assumed that this medium interacts strongly with light at the eigenfrequencies of the atoms ("on the spot"). Therefore, having a large column density of excited hydrogen, this medium amplifies so strongly the lines that its superradiance reduces to the emission of Dicke spikes similar to laser emissions. As in a laser, the competition of the modes leaves only a few rays for which the column density of amplifying atoms is maximal; therefore these bright rays are tangent to the inner rim of the shell, observed into a direction as a dotted ring.
The emissions of the alpha lines help each other, making induced multiphotonic emissions able to de-excite highly excited atoms or atoms of the continuum corresponding to a collision of a proton and an electron. The very hot, polychromatic light emitted by the star may excite the atoms by a mono or multiphotonic pumping; this absorption combines with the emissions into a multiphotonic induced scattering which amplifies the superradiant beams, so that, in despite of a remaining large radiance, the relatively small star is not anymore visible. Sets of coherent Raman scatterings by recoupling of angular momenta in 2s or 2p atoms of hydrogen, packed in parametric interactions, shift the frequencies of spectra.
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