Evidence of Fragmenting Dust Particles from Near-Simultaneous Optical and Near-IR Photometry and Polarimetry of Comet 73P-Schwassmann-Wachmann 3 - AstrophysicsReportar como inadecuado




Evidence of Fragmenting Dust Particles from Near-Simultaneous Optical and Near-IR Photometry and Polarimetry of Comet 73P-Schwassmann-Wachmann 3 - Astrophysics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We report imaging polarimetry of segments B and C of the Jupiter-family Comet73P-Schwassmann-Wachmann 3 in the I and H bandpasses at solar phase angles ofapproximately 35 and 85deg. The level of polarization was typical for activecomets, but larger than expected for a Jupiter-family comet. The polarimetriccolor was slightly red dP-dL = +1.2 +- 0.4 at a phase angle of ~ 35deg andeither neutral or slightly blue at a phase angle of ~ 85deg. Observationsduring the closest approach from 2006 May 11-13 achieved a resolution of 35 kmat the nucleus. Both segments clearly depart from a 1-rho surface brightnessfor the first 50 - 200 km from the nucleus. Simulations of radiation drivendust dynamics can reproduce some of the observed coma morphology, but only witha wide distribution of initial dust velocities at least a factor of 10 for agiven grain radius. Grain aggregate breakup and fragmentation are able toreproduce the observed profile perpendicular to the Sun-Comet axis, but fit theobservations less well along this axis into the tail. The requiredfragmentation is significant, with a reduction in the mean grain aggregate sizeby about a factor of 10. A combination of the two processes could possiblyexplain the surface brightness profile of the comet.



Autor: Terry Jay Jones, David Stark, Charles E. Woodward, Michael S. Kelley, Ludmilla Kolokolova, Dan Clemens, April Pinnick

Fuente: https://arxiv.org/







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