Voyager UVS observations of the Hydrogen Wall

Details Voyager UVS observations of the Hydrogen Wall Voyager UVS observations of the Hydrogen Wall

Dec 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009agufmsh31b..06q&link_type=abstract

American Geophysical Union, Fall Meeting 2009, abstract #SH31B-06

Astronomy and Astrophysics

Astrophysics

[7549] Solar Physics, Astrophysics, And Astronomy / Ultraviolet Emissions

Scientific paper

We compare new results of models of the interplanetary H Lyman alpha intensity background in the outer heliosphere with scans performed by the Voyager 1/2 UVS instruments between 1993 and 2003. This study shows that the excess intensity initially reported by Quemerais et al. (1995) can be explained by models of the hydrogen atoms distribution including effects of the heliospheric interface. The models of the hydrogen atom distribution in the interplanetary medium used in this work have been developed following the numerical scheme presented by Baranov and Malama (1993). Recent improvements are described by Izmodenov et al. (2005). Radiative transfer computations of the interplanetary Lyman alpha intensity are made following a Monte-Carlo approach presented by Quemerais (2000) and Quemerais and Izmodenov (2002). We find that the upwind intensity excess observed in the outer heliosphere and initially reported by Quemerais et al. (1995) can be explained by a full radiative transfer computation. This computation must include a full description of the velocity distributions of the different hydrogen populations that enter the heliosphere after crossing the interface. The excess upwind intensity observed by UVS on Voyager 1 and Voyager 2 can be explained as an emission of the decelerated hydrogen atoms near the stagnation point of the heliopause. Because those atoms are slowed down relative to the main hydrogen flow, photons scattered by them suffer less absorption and are visible at a much larger distance than it is the case for photons scattered by atoms in the main flow. The shape and extent of the excess emission gives information about the decelerated population near the heliopause stagnation point. A detailed comparison between the data and our present model does not show a complete agreement. The modeled intensity excess is larger than the observed one. We will discuss possible improvements to the H distribution model.

Affiliated with

Also associated with

No associations

Rating

Voyager UVS observations of the Hydrogen Wall 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 Voyager UVS observations of the Hydrogen Wall, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Voyager UVS observations of the Hydrogen Wall will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1784050