Since Herschel was launched on May 14th this year, astronomers across the globe have been working hard to test the instrument and find out if it’s working correctly.  Herschel has given us an amazing glimpse of its power during these Performance Verification and Science Demonstration phases, and these show that Herschel is doing better than expected with some beautiful images of the far-infrared sky.  This week, however, is the first time we get a chance to learn about some scientific results based on the observations taken so far.  All I can say is, “wow”.  Here’s an update on the latest results.

Hidden starbirth

Aquila. Credit: ESA and the SPIRE & PACS consortia, the Gould’s Belt Key Programme Consorti

Now for a truly astonishing image.  Here we see Herschel’s view of the Aquila star forming region, located about 1000 light years away in our Galaxy.  The image shows the combination of 50, 150 and 500 microns and the bright regions are areas where large newborn stars are heating up hydrogen gas.  Aquila is a stellar nursery completely invisible to optical telescopes (in fact, this is the first time its been seen in the infrared) and the image shows some pretty neat stuff.  Firstly, in this image alone, astronomers have detected 700 candidates for stellar embryoes (stars which are about to be born).  100 of these candidates are in the protostar phase and are just waiting for the final step to start before they become a fully-fledged star – all they need is for nuclear fusion to ignite in the core and they are ready.  The rest are likely to be in the stage before this.   Secondly, we can clearly see that stars form in clumps along larger filaments of dust and gas (much like pearls on a necklace); these filaments are probably following magentic fields in the region.  More details on this result can be found here.

Credit: ESA and the SPIRE consortia, the Evolution of interstellar dust Key Programme Consortia

Space is wispy

The next image shows that space is filled with wisps and filaments of dust, these filaments could hold embryonic stars if they accumulate enough mass.  This image, combined with all the data from Herschel will help us understand what the dust is made from and how efficiently it shines (which also tells us how much stardust is there).

Dusty spiral arms

Next we see the spiral galaxy M81 with Herschel.  The spiral arms are really clear in this image, and this is astounding since we have never had the resolution or sensitivity to see this kind of structure before at these wavelengths.

Credit: ESA and the SPIRE consortia, the Nearby Galaxy Survey Key Programme Consortia

After 400 years of using visible telescopes and seeing spiral arms a million times before, it may seem a little strange that I am so excited about seeing spiral arms with Herschel.  There are some hints that dust may be being pulled out from the galaxy as in the M86 system above (see the diffuse light in the north), and astronomers have long been looking for evidence for vast amounts of dust being stripped from a galaxy due to the gravitational pull from its close neighbours. However, these two galaxies are in a region of sky where there happens to be a lot of dust from our own Galaxy in front.  This means that we are also looking through the debris in our own Galaxy, and as you can see from the “wispy” image above, there are places where space is filled with lots of dusty filaments.  The material in the north may actually be in our own Galaxy and not associated with M81 so this needs further checking to be sure.

Galaxies galore

Credit: ESA and the SPIRE & PACS consortia, the HERMES Key Programme Consortia

We can also use Herschel to look deep into space and see distant galaxies which were around when the Universe was very young, when the Universe was about a third to a tenth of its present day age.    In this image we are literally detecting thousands of galaxies.  One of the really surprising things we’ve learnt with Herschel, is that we see so many sources like this in the background of our images, far more than we expected.  The colours in this image give an idea how distant the galaxies are.

Complex chemistry

Herschel has not just been busy taking images, it has also used its numerous spectrographs to search for molecules and atoms in galaxies, stars and comets.  One example is the spectra of the famous galaxy Arp220 shown here, which is the result of two giant galaxies merging together.

Credit: ESA and the SPIRE consortia, the Nearby Galaxy Survey Key Programme Consortia

Arp 220 is around 250 million light years away and is undergoing a renewed (and active) period of star formation as a result of the merger which has comrpessed and heated the gas.   Arp 220 is an important “laboratory” for astronomers to test theories on what the first few generations of galaxies would look like.  What we see in this spectrum are emission and absorption features of water and carbon monoxide.  Herschel is the first instrument to allow us to look at spectra in the submillimetre wavebands and the wealth of information it tells us is outstanding.  Not only can we detect water (seen for the first time in emission here), but we can figure out what its temperature and density is.  The latest spectra of the massive giant star VY Majoris shows evidence for hot steam, which is cooling the star in the same way we use steam to cool nuclear reactors in power stations!

So that’s a small introduction into some of the results from Herschel, but there are many more to come, and plenty of work left to do!  Keep up with the latest news here.