File:Infrared NGC 2170.png

NGC 2170 is one of those nebulas which, in visible light, is difficult to forget. So striking are these tendrils of dust once they are fully revealed, one cannot help associating some kind of emotion with it. I personally find it to be dark and brooding.

These dusty star-forming regions tend to also be interesting in infrared, so I decided to see what kind of data was available in the archives. Lo and behold, Spitzer had observed the region in my favorite bands and so I set forth to compose this.

Unfortunately, it was a very troubled procedure. The most important channel—the 8μm one that I use to sharpen the whole image by applying it as a luminosity layer—was terrible. It was full of these blocky edges with some of the tiles having a bunch of extra light stuck in them, presumably from the zodiacal glow. Whatever it all went through (they call it a pipeline) didn't remove all that extra light, so I had to do it myself. I was moderately successful, but there are still things that aren't quite right with it.

Anyway, the bright spot in the center was also so bright that it easily saturated the detectors from both the Spitzer and the WISE telescopes. That does happen all the time, but it seemed extra annoying somehow. What this means simply is that there is a load of star formation going on in there. When looking at these particular infrared bands I find it's easier to think in terms of dust rather than stars, though. Sure, there are points of light that are stars, but it seems to me that without the dust component they'd all be oddly invisible.

Red: Spitzer/MIPS24 (24μm) Green: WISE/W3 (12μm) Blue: Spitzer/IRAC4 (8μm)