I used a public domain NASA image of the Horsehead nebula, removed the noise and errors and optimized the color range and saturation.

You can find the unedited original here: http://www.noao.edu/image_gallery/html/im0661.html

Minimum credit line: T.A.Rector (NOAO/AURA/NSF) and Hubble Heritage Team (STScI/AURA/NASA)