We analyse the ROSAT PSPC spectrum of 19 X–ray selected Narrow Emission Line Galaxies ( NELGs ) discovered during the optical identification of sources in the ROSAT UK Deep Survey .
Their properties are compared to those of broad line Active Galactic Nuclei ( AGN ) in the same sample .

Counts in three spectral bands have been extracted for all the sources , and have been fitted with a power-law model assuming the Galactic value for N _ { H } .
The average slope of NELGs is \alpha = 0.45 \pm 0.09 , whilst for the AGN it is \alpha = 0.96 \pm 0.03 .
The power-law model is a good fit for \sim 90 % of NELGs and \sim 75 % of AGN .

Recent work shows that the fractional surface density of NELGs increases with respect to AGN at faint fluxes .
Thus they are expected to be an important component of the residual soft ( < 2 keV ) X–ray background .
The slope of the X–ray background ( \alpha \sim 0.4 , 1-10 keV ) is harder than that of AGN ( \alpha \sim 1 ) but our results show that it is consistent with the summed spectrum of the NELGs in the deep survey ( \alpha \sim 0.4 ) .
This may finally reconcile the spectrum of the background with the properties of the sources that constitute it .