Документ взят из кэша поисковой машины. Адрес
оригинального документа
: http://star.arm.ac.uk/~dja/papers/abs08EMP.html
Дата изменения: Fri Apr 18 13:30:39 2008
Дата индексирования: Tue Oct 2 03:24:10 2012
Кодировка:
Поисковые слова: ngc253
Abstract:
The spatial structure of meteor streams, and the activity profiles of their
corresponding meteor showers, depend firstly on the distribution of meteoroid
orbits soon after ejection from the parent comet nucleus, and secondly on the
subsequent dynamical evolution. The latter increases in importance as more
time elapses. For younger structures within streams, notably the dust trails
that cause sharp meteor outbursts, it is the cometary ejection model
(meteoroid production rate as a function of time through the several months
of the comet's perihelion return, and velocity distribution of the meteoroids
released) that primarily determines the shape and width of the trail
structure. This paper describes how a trail cross section can be calculated
once an ejection model has been assumed. Such calculations, if made for a
range of ejection model parameters and compared with observed parameters of
storms and outbursts, can be used to constrain quantitatively the process of
meteoroid ejection from the nucleus, including the mass distribution of
ejected meteoroids.