# The Diffuse Radiation Field at High Galactic Latitudes

## TL;DR

This study uses GALEX data to measure the diffuse ultraviolet background at high galactic latitudes, identifying contributions from dust, extragalactic sources, and unexplained components, with implications for understanding galactic and extragalactic radiation.

## Contribution

It provides new measurements of the diffuse UV background at galactic poles and quantifies the contributions from dust, extragalactic sources, and unidentified sources.

## Key findings

- Dust scattered light accounts for about 120 photon units.
- Extragalactic radiation contributes approximately 110-190 photon units.
- Unidentified radiation remains significant, especially in the NUV.

## Abstract

We have used GALEX observations of the North and South Galactic poles to study the diffuse ultraviolet background at locations where the Galactic light is expected to be at a minimum. We find offsets of 230 -- 290 photon units in the FUV (1531 \AA) and 480 -- 580 photon units in the NUV (2361 \AA). Of this, approximately 120 photon units can be ascribed to dust scattered light and another 110 (190 in the NUV) photon units to extragalactic radiation. The remaining radiation is, as yet, unidentified and amounts to $120 -- 180$ photon units in the FUV and $300 -- 400$ photon units in the NUV. We find that molecular hydrogen fluorescence contributes to the FUV when the 100 $\mu$m surface brightness is greater than 1.08 MJy sr$^{-1}$.