Herschel Delivers the Goods

It’s a bit lower key than I’d hoped because of Wednesday’s catastrophic announcements, but some of the first science results from Herschel are now available online. I’ve taken most of the following text from our own Herschel Outreach site here at Cardiff University.

Herschel scientists are currently meeting in Madrid to present the results from the Science Demonstration Phase of the Herschel mission. This is the phase of the mission where the satellite and its instruments are stretched to their full capabilities. A number of results involving the SPIRE instrument and astronomers from the UK have been presented. Professor Matt Griffin, SPIRE Principal Investigator, said

The Herschel Science Demonstration meeting is what the SPIRE team has been looking forward to since the start of the project more than a decade ago, and the results being presented are even better than we dared hope before launch. Not only are the observatory and the instrument working very well, but it is already clear that in this unexplored region of the spectrum, the Universe is even more interesting than we thought.

As well as the images presented below, more scientific results are being presented at the meeting in Madrid, some of which will be shown here in due course. I’ll just show you a quick taster of a couple of the things Cardiff astronomers are looking at.

A region of the Virgo cluster as seen in optical light by Sloan Digital Sky Survey (left) and in far-infrared by SPIRE 250m image Image credit: SDSS (left), ESA/Herschel/HeViCS Key Project (right)

Above is a region of the Virgo cluster, a large cluster of galaxies around 50 million light-years from our galaxy. The left panel shows a region containing four galaxies in optical light, from the Sloan Digital Sky Survey, while the right panel shows the region as seen by SPIRE at 250mm. The galaxies in the Virgo cluster are kept together by their mutual gravitational attraction. However, the galaxies do move relative to each other, and when they pass close to each other they can pull gas and dust into clumps and streams which stretch between the galaxies. Dr Jonathan Davies, of Cardiff University, and Principle Investigator of the Herschel Virgo Cluster Survey, for which this image was taken, commented that “far-infrared observations such as this give us an unprecedented insight into the behaviour of gas and dust in galaxy clusters, and further observations should yield some very exciting results”. The area of emission above the galaxy NGC4435 is very faint as seen in optical light, but much brighter in the far-infrared as measured by SPIRE. Also notable from this region is the relative brightness of the galaxies NGC4406 and NGC4402. NGC4406 is a giant elliptical galaxy, and so very bright in the optical, but is almost invisible in the far-infrared. This shows that it has already used up the majority of its gas and dust in forming the stars.

SPIRE image of the GOODS-North region. Image credit: ESA/Herschel/HerMES Key Project

On the left is shown an area of sky called the “Great Observatory Origins Deep Survey” (GOODS), which has been observed by many telescopes at a range of wavelengths, and now by SPIRE in the far-infrared. It is an area of sky devoid of foreground objects, such as stars within our Galaxy, or any other nearby galaxies, and is a little larger than the area of the full moon as observed from Earth. The image is made from the three SPIRE bands, with red, green and blue corresponding to 500µm, 350µm and 250µm respectively. Every fuzzy blob in this image is a very distant galaxy, seen as they were 3—10 billion years ago when the star formation was very widely spread throughout the Universe. Dr Seb Oliver, of University of Sussex and PI of the HERMES survey for which this image was taken, said

Seeing such stunning images after just 14 hours of observations gives us high expectations for the full length observations over much larger regions of the Universe. This will give us a much clearer idea of how star formation has progressed throughout the history of the Universe.” The redder objects are either more distant, as the expansion of the Universe has stretched, the light more since it was emitted by the galaxy, or much cooler than the bluer galaxies. This is the first time much of the Cosmic Infrared Background, discovered in the 1990s, has been resolved into the individual galaxies. Studying these galaxies at this early stage of the Universe will allow astronomers to test their models of star and galaxy formation.

I’d add that although this is probably the least photogenic of the images just released, it’s the sort of thing that fascinates those of us of a statistical persuasion because it’s such a challenge to wring as much science as possible from data that test the limits of the instrument’s capabilities. However it takes a great deal of time and detailed analysis to do justice to the quantity and quality of the data that’s coming in from Herschel. If our grants  get cut then we’ll find it very difficult to deliver this science in a timely fashion, and that would be a ridiculous state of affairs given the investment that’s already gone in to building this marvellous observatory.

5 Responses to “Herschel Delivers the Goods”

  1. […] This post was mentioned on Twitter by Garth Godsman, Peter Coles. Peter Coles said: Herschel Delivers the Goods: http://wp.me/pko9D-19u […]

  2. Peter – stunning results indeed. The GOODS image is just a tad TOO good. Its so deep its confused. I can see how a statistics nut like yourself would see this as fun rather than a problem…

  3. telescoper Says:

    Confusion is good. It’s a Zen thing.

    It was pretty certain that Herschel would reach the confusion limit very quickly and that’s clearly what has happened with the GOODS image. There’s still a huge amount of information in there though, and it will be very interesting to see how much can be squeezed out.

  4. Mark McCaughrean Says:

    The colour GOODS-N image is indeed brilliant, but it says clearly “time to move to a new pointing”. Which Herschel did, of course: both Seb and Steve Eales showed some much, much wider field extragalactic images yesterday that looked like POSS plates from a distance 🙂

    And this all with just a small fraction of the Key Project datasets collected to date …

    Both this image and the Aquila star-formation pretty picture seen on the web were shown at ESA Council earlier this week and were very positively received. And Mike Griffin, former NASA administrator, sent a very complimentary message to Jean-Jacques Dordain, ESA DG, and David Southwood, Director of Science & Robotic Exploration, after having seen the images on the BBC.

    Herschel’s doing very well and we’re looking forward to a recovery of HIFI after Christmas, hopefully …

  5. […] preliminary results from the Science Demonstration Phase of Herschel’s operations. I did a quick post about some of the results, but didn’t have time to cover everything, which I still […]

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