AEROSOL DEBRIS IN THE CORE AND CRESCENT-SHAPED REGIONS OF COMET-P SHOEMAKER-LEVY-9 H-FRAGMENT AND G-FRAGMENT IMPACT SITES ON JUPITER

We report on the physical properties of the particles produced after t he collision of fragments E, G, and H of Comet Shoemaker-levy 9 with J upiter on July 1994. CCD images were acquired at the 4.2-m William Her schel Telescope at La Palma (Spain) through three filters centered at 3600, 8920, and 9480 Angstrom. Radiative transfer models in combinatio n with a Mie scattering code were used to retrieve the possible values of the aerosol properties compatible with these observations, We used images of the fresh H impact site (2 hr after the fragment collision) and images of the G impact site (13 hr after impact) to analyze the d ense cores of the collision sites as well as the particles of debris i n the crescent-shaped ejecta of the two mentioned impacts, While the b est-fit model for the particles in the H core and ejecta clouds corres ponded to a log-normal radius of 0.15 +/- 0.02 mu m and an imaginary i ndex of 0.020 +/- 0.004 (at 3600 Angstrom) and 0.006 +/- 0.003 (at the near infrared), those of the G impact corresponded to values of 0.20 +/- 0.01 mu m for the radius and 0.030 +/- 0.004 and 0.009 +/- 0.003 f or the imaginary refractive indices at 3600 and at 8920 and 9480 Angst rom, respectively, We also found that in the core regions most of the particles were concentrated in the region 300-450 mbar, whereas within the crescent-shaped areas, the particles were more uniformly distribu ted in height between pressures less than 1 mbar and 450 mbar. The eje cta cloud contained only one-third (case H) or one-fifth (case G) of t he total number of particles in the core. (C) 1997 Academic Press.