We use galaxies detected in a deep ultraviolet XMM-Newton Optical Monitor image and a model that predicts UV galaxy counts based on local counts and evolution parameters to constrain galaxy evolution to Z=1.2 .
The 17 ’ square 2000 Å ( UVW2 filter ) image was taken as part of the XMM-OM team ’ s guaranteed time program .
We detect sources in this image to a flux limit of 2.7 \times 10 ^ { -17 } ergs cm ^ { -2 } s ^ { -1 } Å ^ { -1 } ( AB magnitude = 22 ) .
Since some of the sources may be stars , we perform a number of checks , including shape , color and implied distance to remove stars from the detected counts .
We find galaxy number counts as a function of magnitude roughly in agreement [ ] tsasseen-F7 : milliard92 , but again find these counts are in excess of evolution models .
The excess counts at faint magnitudes may provide evidence for either a new population of galaxies emerging around Z=0.7 or more dramatic evolution than some earlier predictions .
The integrated light from the detected galaxies totals 32–36 ph cm ^ { -2 } s ^ { -1 } Å ^ { -1 } sr ^ { -1 } , placing a firm lower limit on the integrated UV light from galaxies .