Nature of the Warm Excess in eps Eri: Asteroid belt or Dragged-in Grains

Eps Eri and its debris disk provide a unique opportunity to probe the outer zones of a planetary system due to its young age (roughly 1 Gyr) and proximity (3.22 pc, the closest prominent debris disk by more than a factor of two). It is the Rosetta Stone for more distant exoplanetary debris systems and thus critical to understanding the mid-term evolution of our Solar System. From resolved images in the far-infrared and submillimeter along with spectra from 10-35 and 55-95 microns, the eps Eri disk was suggested to have a complex structure, with multiple zones in both warm (asteroid-like) and cold (KBO-like) components. Alternatively, the warm excess can also originate from small grains in the cold disk, which are transported inward by the combination of Poynting-Robertson and stellar wind drags. Here we present a SOFIA/FORCAST 35 micron image of the system, and provide additional constraints on the nature of the warm excess inferred fromprevious Spitzer and Herschel observations.