Michael
I think its the Lagoon nebula. I took the liberty of copying your image to try and subtract the noise.
I used Photoshop and did the following (basic process from Scott Irelands book)
1. Made a duplicate layer
2. Made a mask within the duplicate
3. Desaturated the duplicate and copied it into the mask
4. Inverted the mask and adjusted the level to be darker
5. Removed the link from the duplicate to the mask
6. Did a gaussian blur on the duplicate (about 150)
7. Flattened the image and saved as a JPEG
Its a good book - its helping me out a lot and i,m up to about page 101
theres lots of trial and error involved (more error than trial usually on my part)