Session 5 - Solar System Objects.
Display session, Monday, June 09
South Main Hall,

## [5.01] Distribution of the Resonant Particles in the Zodiacal Cloud: a New Approach

N. Gor'kavyi (Crimean Obs.), L. Ozernoy (CSI/GMU and GSFC/NASA), J. Mather (GSFC/NASA), T. Taidakova (Crimean Obs.)

As we have shown earlier, the interplanetary dust flow evolution can be conveniently described by the continuity equation written in the space of orbital coordinates such as semimajor axis a, eccentricity e, inclination i, etc. (Gor'kavyi, Ozernoy, amp; Mather 1997). Having accounted for the Poynting-Robertson (P-R) drag as the leading effect for dynamics of small dust particles, we have computed a `reference model' for the 3-D structure of the zodiacal cloud produced by 217 comets and 5000 asteroids (Gor'kavyi, Ozernoy, Mather amp; Taidakova 1997 \equiv GOMT). In order to make our reference model complete, one needs to include in it those \sim 10% of particles which are subjected to resonant effects.

For a resonant line a=const in the (a,e)-space, we solve analytically a new 1-D transport equation (see GOMT) and then find the distribution of resonant particles in the zodiacal cloud. This enables us to compute the (a,e)-distribution of resonant particles in the zodiacal cloud for about two dozen different resonances near Earth. Using our transformation equations, we make a transition from the space of orbital coordinates to the r,z-space, which completes the finding of the resonant ring near the Earth averaged over the direction of particle's perihelion. We calculate the number densities and masses of the asteroidal and cometary components of the resonant and non resonant populations of the zodiacal cloud near the Earth. A substantial advantage of this approach is that, as opposed to previous work on resonant particles, it enables us to compute the particle's distribution in eccentricity in the vicinity of every resonant orbit.

References: \footnotesize Gor'kavyi, N., Ozernoy, L. amp; Mather, J. 1997, ApJ 474, 496. Gor'kavyi, N., Ozernoy, L., Mather, J. amp; Taidakova, T. 1996, Bull. AAS 28, 1300; \hbox ApJ 1997 (submitted) (\equiv GOMT)