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D. E. Dunn (Sierra College), M. Wright, I. de Pater (University of California at Berkeley), M. Hogerheijde (University of Arizona), L. A. Molnar (Calvin College)
In the past eight years we have examined the microwave emissions of Saturn's rings and atmosphere at wavelengths ranging from 0.7 to 21-cm. At these wavelengths, the primary contribution of flux from the rings is scattered Saturnian thermal emission. However, at shorter (mm) wavelengths, a significant contribution from the ring's own thermal emission should begin to emerge.
To examine this feature, we present high quality data from the Berkeley-Illinois-Maryland Association (BIMA) and Owens Valley Radio Observatory (OVRO) arrays. We observed at wavelengths of 1.3 and 3.0-mm in October 2002 and March 2003, respectively. At that time Saturn's rings were near their maximum ring opening angle (|B| ~26.5 deg), projecting the largest ring area possible, allowing us to adequately map the brightness temperature of the rings even with the moderate resolution achieved (~3.0'').
As with previous observations, we use our radiative transfer code (Dunn et al., Icarus 160, 132--160 [2002]) to model the relative contributions of the scattered and thermal radiation emanating from the rings and compare the results to that seen in the data. However, unlike the previous (centimetric) observations, the present (millimetric) data serves as an adequate test of the model's ability to account for the thermal contribution of the rings.
This work was supported in part by NASA grant NAG5-13349 and NSF grant AST-9981308.
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Bulletin of the American Astronomical Society, 35 #4
© 2003. The American Astronomical Soceity.