Herschel’s cameras combine to show the galaxy in a new light

The Herschel Space Observatory has produced spectacular new images of interstellar material in our galaxy, using the UK-led SPIRE camera in tandem with Herschel’s other camera, PACS.

The new pictures, made during the first trial run with the two instruments operating at the same time, have unveiled a small part of our Milky Way Galaxy as we have never seen it before, and bode well for one of Herschel’s main scientific projects, which is to survey large areas of the galaxy.

Professor Keith Mason, Chief Executive of the Science and Technology Facilities Council (STFC), which provides the UK funding for Herschel, said “SPIRE has produced some spectacular new images. This sophisticated camera is evidence of the skill and cutting edge technology we have here in the UK and is set to vastly expand our knowledge of the early stages of our Universe.”

The SPIRE camera responds to light at wavelengths between 250 and 500 microns (millionths of a metre) - 500-1000 times longer than the wavelength of visible light - and PACS covers wavelengths between 70 and 170 microns. Together they provide detailed images in five different far infrared colours, not only revealing new material in the Galaxy, but providing astronomers with a wealth of information about it - such as how much material there is, its mass, temperature and composition, and whether or not some of it is collapsing to form new stars. Stars form in cold, dense environments, and the composite images locate the star-forming regions that would be very difficult to isolate from a map made at a single far-infrared or submillimetre wavelength.

The two instruments have imaged an area of about 2 x 2 degrees (about 16 times as big as the size of the Moon as seen from Earth), revealing an extremely rich reservoir of cold material in the Galactic Plane which is seen to be in a previously unsuspected state of turmoil. The interstellar material is condensing in a continuous and interconnected maze of filaments and strings of newly forming stars in all stages of development, unveiling a tireless Galaxy constantly forging new generations of stars. We see an intricate network of filamentary structures with surprising features indicative of a chain of near-simultaneous star-formation events, glittering rather like beads of water on a string in the sunlight.

Large areas of the Milky Way will be systematically surveyed by Herschel in
this manner, helping astronomers to unravel the mysteries of star formation in a way that has never been previously possible. With the two instruments operating at the same time, the observations can be made with great efficiency.

Professor Matt Griffin of Cardiff University, who is the SPIRE Principal Investigator, said: “We had high hopes for this kind of observation with Herschel, using the combined power of the two cameras to see the galaxy as never before. It’s great to see that the observations work so well from a technical point of view, and that the scientific results are so spectacular. It appears that star formation in the galaxy is a very turbulent process.”

Dr David Clements from the SPIRE team at Imperial College London’s Department of Physics added: “These images show SPIRE and PACS working together in perfect harmony, something that will be needed not only for studies of our own galaxy but also for Herschel's large UK-led studies of galaxy evolution. It also demonstrates the UK's instrumentation expertise for future far-IR space missions.”


Notes for editors

Images

 

[Fig 1] Three-colour composite image made from the SPIRE observations at wavelengths of 250, 350 and 500 microns (Credit: ESA)


In this SPIRE image the blue colour denotes emission at 250 microns, green 350 microns, and red 500 microns. The colour-coding differentiates material that is extremely cold (red) from that which is warmer.

[Fig 2] Two-colour composite image made from the PACS observations at wavelengths of 70 and 160 microns (Credit: ESA)

In this PACS image, cyan denotes 70 micron emission and the red shows emission at 160 microns.

 

[Fig 3] Five-colour composite image of a 2 x 2 degree area in the plane of our Galaxy, combining the PACS and SPIRE observations (Credit: ESA)

In this image the SPIRE and PACS images have been combined into a single composite; here the blue denotes 70 microns, the green 160 microns, and the red is the combination of the emission from all three SPIRE bands at 250/350/500 microns.

 

[Fig 4] SPIRE beam steering mechanism, built at the UK ATC, Edinburgh


 

 

 

Herschel and SPIRE
The European Space Agency’s Herschel satellite carries the largest telescope to be flown in space and will study the Universe at far infrared wavelengths. It will reveal the early stages of star birth and galaxy formation; it will examine the composition and chemistry of comets and planetary atmospheres in the Solar System; and it will examine the star-dust ejected by dying stars into interstellar space which form the raw material for planets like the Earth.

The SPIRE instrument has been built by a consortium of 18 institutes in eight countries (UK, France, Italy, Spain, Sweden, USA, and China), led by Prof. Matt Griffin of Cardiff University. The instrument was assembled at the STFC’s Rutherford Appleton Laboratory in the UK.


Herschel Images
Images of Herschel are available from the STFC Press Office

Herschel Mission timeline:
• Herschel and Planck were launched on an Ariane 5 from Europe’s Spaceport in Kourou, French Guiana, on 14 May 2009.
• Commissioning Phase: In the first few days after launch basic spacecraft checks were done. One to two weeks after launch, the Herschel scientific instruments were switched on for the first time and detailed commissioning of the instruments began. This will continue until around the end of July. The satellite is already nearing its operational orbit, about 1.5 million km from the Earth.
• Performance Verification Phase: This began 60 days after launch, and will continue until mid-October. It involves tests to ensure that the instrument operational modes and scientific data processing software are thoroughly checked and optimised.
• Science Demonstration Phase: About 150 days into the mission, spacecraft and instrument testing will be complete and comprehensive trial scientific observations will begin, involving execution of a selection of different kinds of observations and processing the data to produce scientific results.
• Routine Operations Phase: About six months after launch, routine operations will begin, and will last for at least three years. The observational programmes for the first 18 months have already been selected.


Contacts

Julia Short
Press Officer
STFC
Tel: +44 (0)1793 442 012
Email: Julia.short@stfc.ac.uk

Prof. Matt Griffin
Herschel-SPIRE Principal Investigator
School of Physics and Astronomy
Cardiff University
Tel: +44 (0)29 2087 4203
Email: matt.griffin@astro.cf.ac.uk

UK Participation in Herschel

The UK contribution to Herschel includes leadership of the international consortium that designed and built the SPIRE instrument. The UK SPIRE team is also responsible for the development of software for instrument control and processing of the scientific data, and leads the in-flight testing and operation of SPIRE. The Herschel programme in the UK is funded by the Science and Technology Facilities Council.

SPIRE comprises a three band imaging photometer and an imaging Fourier transform spectrometer and has been designed and built by a consortium of institutes including a number from the UK (Cardiff University; Imperial College, London; the Mullard Space Science Laboratory; the University of Sussex; and STFC’s Rutherford Appleton Laboratory and UK Astronomy Technology Centre). The UK is also leading the development of software for controlling the instrument from the ground and processing the data to produce scientific results. The SPIRE Operations Centre, responsible for delivering all instrument software to ESA, and for day-to-day instrument monitoring, operation, and calibration, is located at the Rutherford Appleton Laboratory with contributions from the Imperial College and Cardiff groups. The UK SPIRE institutes, together with astronomers in many other UK universities, are also strongly involved in the Herschel scientific programmes which have already been selected for the first 18 months of Herschel observations, and cover a wide range of science topics from our own solar system to the most distant galaxies.


Science and Technology Facilities Council (STFC)

The Science and Technology Facilities Council ensures the UK retains its leading place on the world stage by delivering world-class science; accessing and hosting international facilities; developing innovative technologies; and increasing the socio-economic impact of its research through effective knowledge exchange.

The Council has a broad science portfolio including Astronomy, Particle Physics, Particle Astrophysics, Nuclear Physics, Space Science, Synchrotron Radiation, Neutron Sources and High Power Lasers. In addition the Council manages and operates three internationally renowned laboratories:

• The Rutherford Appleton Laboratory, Oxfordshire
• The Daresbury Laboratory, Cheshire
• The UK Astronomy Technology Centre, Edinburgh

The Council gives researchers access to world-class facilities and funds the UK membership of international bodies such as the European Laboratory for Particle Physics (CERN), the Institute Laue Langevin (ILL), European Synchrotron Radiation Facility (ESRF), the European organisation for Astronomical Research in the Southern Hemisphere (ESO) and the European Space Agency (ESA). It also funds UK telescopes overseas on La Palma, Hawaii, Australia and in Chile, and the MERLIN/VLBI National Facility, which includes the Lovell Telescope at Jodrell Bank Observatory.
The Council distributes public money from the Government to support scientific research.

The Council is a partner in the UK space programme, coordinated by the British National Space Centre.