# The Inner 25 AU Debris Distribution in the epsilon Eri System

## TL;DR

This study uses multi-wavelength imaging to analyze the inner debris distribution of epsilon Eri, concluding that in-situ planetesimal belts are the primary source of inner disk dust, with some contribution from dragged-in grains.

## Contribution

It provides the first high-resolution SOFIA 35 um image of epsilon Eri's debris disk and combines it with other data to distinguish between proposed origins of inner debris.

## Key findings

- In-situ planetesimal belts are the main source of inner debris.
- Dragged-in grains from the outer belt contribute but are not the sole source.
- High-resolution imaging rules out the entire inner excess being from dragged-in grains.

## 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.