The great images from Herschel continue to come in. This week ESA released the first image that combines data from two of its instruments, PACS and SPIRE.While each instrument has its own unique functionality, the true power of a multi-mode observatory like Herschel is often the ability the observe the same region of sky with several of its instruments simultaneously, to offer a richer view of the target than possible with a single instrument.
This particular image shows a region of active star formation in the plane of our Galaxy, located in the constellation of the Southern Cross. It combines data from five different infrared wavebands (three from SPIRE, two from PACS) to reveal an immense amount of complexity, with lots of dark pockets, bright spots and stretched-out filaments. While the picture may look very fiery on the surface, the stuff seen by Herschel is all essentially cold, with some of the reddest regions in this image only a few degrees above absolute zero. Stars are formed in cold, dense, molecule-rich environments – and this kind of material emits most of its light in the far-infrared, where Herschel’s instruments are sensitive.
When you say “Herschel”, I still think William Herschel