As the NASA caption below explains this is composite image of the Crab Nebula from Hubble and Herschel. ESA has a nice explanation of the Herschel data along with links to an image and a portion of spectrum. Active Argon? Cool stuff!
From NASA (larger versions of the image available here):
This image shows a composite view of the Crab nebula, an iconic supernova remnant in our Milky Way galaxy, as viewed by the Herschel Space Observatory and the Hubble Space Telescope. Herschel is a European Space Agency (ESA) mission with important NASA contributions, and Hubble is a NASA mission with important ESA contributions.
A wispy and filamentary cloud of gas and dust, the Crab nebula is the remnant of a supernova explosion that was observed by Chinese astronomers in the year 1054.