Back in June and July Stuart and I talked about the very first images from PACS and SPIRE, two of the three instruments onboard the Herschel Space Telescope (for those of you who were wondering, the third instrument, HIFI, is currently switched off due to a malfunction but it should be back working properly soon). Well, the PACS and SPIRE cameras can also be operated in the versatile ‘Parallel Mode’ in which they observe the same patch of sky simultaneously. This is a very efficient way to take images in all of Herschel’s five available infrared wavelengths (3 from SPIRE, and 2 from PACS), and will eventually be used to survey large areas of the sky quickly.
The stunning picture at the top of this post is the result of colouring and combining all five images from the first trial Parallel Mode run. It shows an area of the Milky Way (our own galaxy) about 16 times bigger than the area of the full Moon (that’s 2×2 square degrees). Herschel is designed to see the cold clouds of dust and gas that are invisible to other telescopes like Hubble. In this case the clouds are surrounding newly forming stars – the turmoil suggested by all the twisting filaments makes this an exciting place to be born!
Herschel is now approaching the end of its testing and calibration phase and will soon begin what’s known as ‘science demonstration’, in which it will test out a range of different observations to make sure it’s performing as expected. The first science data has already gone to a select few astronomers – I think things are going to get very busy, very soon!
A couple of weeks ago ESA released the first images from the PACS instrument onboard the Herschel Space Telescope. This morning it followed them up with the equally impressive first light images from the longer wavelength, UK led, SPIRE instrument.
The images above show two spiral galaxies, M66 and M74. The wavelengths at which SPIRE operates means that it sees the glow from cold clouds of dust which occur in regions where lots of star formation is occurring (this is why the spiral arms show up so clearly). Even more interesting for me though are all the blobs that can be seen in the background to the images – each one is actually a much more distant galaxy, too far away from us to be seen as anything other than a point source. As the speed of light is always the same, looking at these galaxies is like looking back in time; the light Herschel has detected was emitted many, many years ago and has been travelling towards us ever since. This means that studying these objects can tell us about what things were like in the Universe when it was young.
This picture compares two images of the same nearby spiral galaxy, M74, one taken with the Spitzer Space Telescope and the other taken with the SPIRE instrument. It illustrates how much more detail Hershchel can see with its larger (3.5 m) mirror and more sensitive detectors.
More images from these first observations can be found here and see here for the UK Herschel Outreach Site which gives a good overview of the mission, including a fun counter showing how far away the satellite currently is along with how fast its now moving.
The quality of these images is amazing given that they were taken before the telescope’s been properly set up. I think it’s like buying a new TV, turning it on for the first time, and being able to start watching it after only half tuning it in. It’s all very exciting!