Aerosol debris in the core and crescent-shape regions of Comet P/Shoemaker-Levy 9 H and G fragment impact sites on Jupiter

Publication date: 
Main author: 
Molina A.
IAA authors: 
Molina A.;Moreno F.;Muñoz O.
Molina A., Moreno F., Muñoz O.
Publication type: 
We report on the physical properties of the particles produced after the collision of fragments E, G, and H of Comet Shoemaker-Levy 9 with Jupiter on July 1994. CCD images were acquired at the 4.2-m William Herschel Telescope at La Palma (Spain) through three filters centered at 3600, 8920, and 9480 Å. Radiative transfer models in combination 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 dense cores of the collision sites as well as the particles of debris in the crescent-shaped ejecta of the two mentioned impacts. While the best-fit model for the particles in the H core and ejecta clouds corresponded to a log-normal radius of 0.15 ± 0.02 μm and an imaginary index of 0.020 ± 0.004 (at 3600 Å) and 0.006 ± 0.003 (at the near infrared), those of the G impact corresponded to values of 0.20 ± 0.01 μm for the radius and 0.030 ± 0.004 and 0.009 ± 0.003 for the imaginary refractive indices at 3600 and at 8920 and 9480 Å, 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 distributed in height between pressures less than 1 mbar and 450 mbar. The ejecta cloud contained only one-third (case H) or one-fifth (case G) of the total number of particles in the core. © 1997 Academic Press.