Problems with non-thermal models for the narrow line gamma rays reported from SS 433 |
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Authors: | J. C. Brown V. A. Carlaw T. V. Cawthorne V. Icke |
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Affiliation: | 1. Department of Physics and Astronomy, University of Glasgow, Scotland, U.K.
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Abstract: | The jet/grain model proposed by Ramatyet al. (1984, hereafter abbreviated as RKL) for production of the narrow gamma-ray lines reported from SS433 is examined and shown to be untenable on numerous grounds. Most importantly: - The huge Coulomb collisional losses (W c?2×1041 erg s?1) from the jet, which would necessarily accompany non-thermal production of the gamma rays, demands a jet acceleration/collimation process acting over a very long range and with a power at least 102 times the Eddington limit for any stellar object.
- There is a collisional thick target limit (irrespective of jet mass) to the gamma ray yield per interstellar proton. Consequently, the gamma-ray data demand an improbably high interstellar density (?109 cm?3).
- For the grains to be kept cool enough (?3000 K) to survive the heating rateW c either by radiation or jet expansion would demand a ‘jet’ wider than its length and so inconsistent with narrow lines. In the case of radiative cooling, the resultant IR flux would exceed the observed values by a factor ?104.
- Light scattered on the jet grain mass required would be highly polarized, contrary to observations, unless the jet was optically thick to grains, again precluding their radiative cooling.
- To avoid unacceptable precessional broadening of the gamma-ray lines demands an emitting jet length ?0.5 days atv=0.26c. This increases the necessary mass loss rate by a factor ?10 over the values obtained by RKL who assumed a 4-day ‘flare’.
- The model also predicts rest energy gamma-ray lines which are not observed.
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