Observations of Far-Ultraviolet Diffuse Emission from the Small Magellanic Cloud

Abstract

We report the first observations of far-ultraviolet (FUV: 1000 -- 1150 Ã ) diffuse radiation from the Small Magellanic Cloud (SMC) using observations from the {\em Far Ultraviolet Spectroscopic Explorer (FUSE)}. The strength of FUV diffuse surface brightness in the SMC ranges from the detection limit of 2000 photons cm${}^{-2}$ s${}^{-1}$ sr${}^{-1}$ Ã ${}^{-1}$ to a maximum of $3\times 10^5$ photons cm${}^{-2}$ s${}^{-1}$ sr${}^{-1}$ Ã ${}^{-1}$ at 1004 Ã . The contribution of diffuse emission to the total radiation field was found to be 34% at 1004 Ã to 44% at 1117 Ã with a maximum observed uncertainty of 30%. There is a striking difference between the FUV diffuse fraction from the SMC and the Large Magellanic Cloud (LMC) with the SMC fraction being higher probable because the higher dust albedo. The FUV diffuse emission correlates with H$\hat{I}\pm$ emission in the H {\small II} regions of the SMC.

Accepted for publication in ApJ