Now, I am not really a fan of posting "pretty pictures" of astronomy, it doesn't do them justice to be seen as just pretty pictures. Well, I'll post some that I find interesting. Someone has posted pictures of the Andromeda galaxy in visible light, I'll post it again just as a reference for this series. The images aren't oriented and aligned properly, sorry about that.
If we were to look at Andromeda it would look something like this.
It's a great example of a spiral galaxy, this particular one is headed our way at 300 kilometres per second.
Click for the high-res picture
This is the same galaxy, the only difference now is that we're looking it infrared, thanks to the Spitzer Space Telescope. We can see straight past through the dust that blocks our view in the visible spectrum. This image is quite peculiar, what we're looking at clusters of gas and dust.
Click to see in high-res...it's worth it.
This picture comes from the Swift telescope which looks out for gamma-ray bursts. This picture is taken in ultraviolet light, this kind of light comes from very hot gas and new born massive stars. It's quite a different view than IR.
You know the deal.
This picture is a composite image, the blue light in this image is in the x-ray spectrum and the orange light is in far infrared. Amazingly hot material, material falling into black holes and material around neutron stars get really hot and emit x-rays. Really cold dust in the spiral arms, which is carved out beautifully, glows in far IR.
This final image is just eye candy, it's a favourite of mine. It was taken by the WISE, this image is in different wavelengths of IR light. Star forming regions in this image are coloured pinkish, the orange stuff is cold dust and the blue colour comes from old stars, they aren't resolved in this image that's why it appears to be a blue haze.
So, there we have it, lots interesting images of just one galaxy, they're all beautiful and each sheds a different light on our galactic neighbour and helps us understand it a bit better.