Astronomy and Astrophysics – Astrophysics
Scientific paper
May 1996
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996a%26a...309..957s&link_type=abstract
Astronomy and Astrophysics, v.309, p.957-969
Astronomy and Astrophysics
Astrophysics
20
Radiation Transfer, Interplanetary Medium, Solar Neighbourhood
Scientific paper
The radiation transport equation for solar HI-Lyman Alpha line photons in the interplanetary medium is solved by an expansion of the luminosity function into scattering orders. The solution introduces the exact redistribution function which takes into account the local thermodynamical conditions of the scattering agent, like temperature, density and bulk velocity of the neutral interplanetary hydrogen. Also the actually observed solar HI-Lyman Alpha emission profile will be taken into account. With the simplifying assumption of a constant temperature and bulk velocity of the hydrogen it is then possible to numerically solve the radiation transport equation with an adaptive Gauss-Legendre integration for photons of the first and the second scattering order. The result of this calculation astonishingly enough gives a less satisfying fit of experimental Lyman-Alpha data (like those by Pioneer-10, Voyager 1/2) than that obtained with optically thin approximations which, however, also clearly fail to describe the data satisfactorily well at large solar distances. As we can show here results from multiscattering calculations are fairly sensitive to local variations of the temperature and the bulk velocity of the interstellar hydrogen. If the latter are properly taken into account, fits of the data can be much improved. Though a fully satisfying fit as we show, can only be achieved with improved hydrogen models. Our results also imply that photons of the second and of higher scattering orders only play a minor role and in most cases can even be neglected. According to these experiences in multiscattering calculations we have developed a first order multiscattering code that takes account of the spatial variations in the temperature and bulk velocity of interplanetary hydrogen given by the recent model by Osterbart & Fahr. With these calculations we can give satisfactorily good fits both of upwind and downwind heliospheric Lyman-α glow data as well.
Fahr Hans Jörg
Scherer Hansjoerg
No associations
LandOfFree
H Lyman alpha transport in the heliosphere based on an expansion into scattering hierarchies. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with H Lyman alpha transport in the heliosphere based on an expansion into scattering hierarchies., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and H Lyman alpha transport in the heliosphere based on an expansion into scattering hierarchies. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1351417