Title: The Inner 25 AU Debris Distribution in the epsilon Eri System,
Abstract: Debris disk morphology is wavelength dependent due to the wide range of
particle sizes and size-dependent dynamics influenced by various forces.
Resolved images of nearby debris disks reveal complex disk structures that are
difficult to distinguish from their spectral energy distributions. Therefore,
multi-wavelength resolved images of nearby debris systems provide an essential
foundation to understand the intricate interplay between collisional,
gravitational, and radiative forces that govern debris disk structures. We
present the SOFIA 35 um resolved disk image of epsilon Eri, the closest debris
disk around a star similar to the early Sun. Combining with the Spitzer
resolved image at 24 um and 15-38 um excess spectrum, we examine two proposed
origins of the inner debris in epsilon Eri: (1) in-situ planetesimal belt(s)
and (2) dragged-in grains from the cold outer belt. We find that the presence
of in-situ dust-producing planetesmial belt(s) is the most likely source of the
excess emission in the inner 25 au region. Although a small amount of
dragged-in grains from the cold belt could contribute to the excess emission in
the inner region, the resolution of the SOFIA data is high enough to rule out
the possibility that the entire inner warm excess results from dragged-in
grains, but not enough to distinguish one broad inner disk from two narrow
belts.