New Constraints from the Wide-field Infrared Survey Explorer (WISE) Data on the 17 Degree Inclination Partial Dust Band and the Emilkowalski Asteroid Disruption

Abstract:

Zodiacal dust bands are a fine structure component of the solar system debris disk. The dust bands are directly linked to the disruption of specific asteroid sources and have been studied to better understand the asteroidal contribution to the zodiacal cloud. Partial dust bands are very young bands that are still in the process of forming and retain crucial information on their parent body disruption (and can even help determine surface properties of the precursor asteroid like regolith depth), since the material composing the young structure has not yet been altered or lost to collisional and orbital decay. Previously, a partial dust band discovered in coadded InfraRed Astronomical Satellite data was linked to the Emilkowalski asteroid cluster.

The WISE dataset represents a very high sensitivity all-sky survey, but the high-level data products were processed in a way that blurred extended emission structures such as the dust bands. Starting with the lowest level data made publically available, we reprocessed the data to produce an all-sky dataset that achieved the high sensitivity, but preserved the extended emission structures.

This new dataset now allows us to examine the dust band structures in unprecedented detail and to refine constraints on the parameters of dust bands and their source bodies. Here we present our latest constraints on the youngest known dust band, the still-forming band at an inclination of 17 degrees to the ecliptic that has been associated with the 220 kyr old Emilkowalski asteroid cluster. By modeling the orbital evolution of dust particles from the source region in the main belt into the inner solar system, we can produce synthetic thermal emission observations and compare them directly with the WISE dataset. Using this method, we can place constraints on the parameters of the dust band and the parent body disruption that created it including: cluster age, longitudinal extent of the band, particle-size distribution and cross-sectional area of material composing the band.

In summary, a reprocessed version of the WISE dataset, tuned to preserve extended emission structures, has given us a new look at a young, still-forming zodiacal dust band, allowing us to further refine our models of the formation of the 17 degree partial band and the disruption of its precursor, the Emilkowalski asteroid cluster.