Headlines > News > Spectacular new observations from the Herschel Space Observatory

Spectacular new observations from the Herschel Space Observatory

Published by Sigurd on Fri Nov 27, 2009 7:55 pm via: source
Share
More share options
Tools
Tags

The European Space Agency has released spectacular new observations from the Herschel Space Observatory, including the UK-led SPIRE instrument.  Spectrometers on board all three Hershel instruments have been used to analyse the light from objects inside our galaxy and from other galaxies, producing some of the best measurements yet of atoms and molecules involved in the birth and death of stars.

The SPIRE Fourier Transform Spectrometer (FTS), which covers the whole submillimetre wavelength range between 194 and 672 microns, will be invaluable to astronomers in determining the composition, temperature, density and mass of interstellar material in nearby galaxies and in star-forming clouds in our own galaxy.

Professor Keith Mason, Chief Executive of the Science and Technology Facilities Council (STFC), which provides the UK funding for Herschel, said “Herschel has once again returned some spectacular indications of what is to come.  This wealth of new data exists because of the dedication and skill of the scientists working on this project and will vastly expand our knowledge of the life cycle of stars.

The exquisite sensitivity and quality of these early data reveal spectacular spectroscopic signatures that show the diversity and complexity of the birth processes common to the formation of star and planets. Herschel is going to help us trace the evolution and life of stars, to map the chemistry in our galactic neighbourhood, and allow us to detect water and complex molecules in distant galaxies.” said Professor Glenn White, of the Open University and STFC’s Rutherford Appleton Laboratory, and an expert in the field of molecular astronomy for which the SPIRE spectrometer is designed

SPIRE spectrum of the giant star VY Canis Majoris, with the inset showing the star as seen by the SPIRE camera.  Image credits: Herschel/SPIRE "MESS" consortium.

SPIRE spectrum of the giant star VY Canis Majoris, with the inset showing the star as seen by the SPIRE camera. Image credits: Herschel/SPIRE "MESS" consortium.

Shows part of  the SPIRE spectrum of VY Canis Majoris (VY CMa), a giant star near the end of its life, which is ejecting huge amounts of gas and dust into interstellar space, including elements such as carbon, oxygen and nitrogen (which form the raw material for future planets, and eventually life).  The inset is a SPIRE camera image of VY CMa, in which it appears as a bright point-source near the edge of a large extended cloud.  The spectrum is amazingly rich, with prominent features from carbon monoxide (CO) and water (H2O).  More than 200 other spectral features have also been identified, many due to water, showing that the star is surrounded by large quantities of hot steam. Observations like these will help to establish a detailed picture of the mass loss from stars and the complex chemistry occurring in their extended envelopes.

SPIRE spectrum of part of the Orion Bar in the Orion Nebula, showing the methylidynium emission line in amongst the CO lines.  Image credits: ESA/Herschel/SPIRE "Evolution of Interstellar Dust" consortium and NASA/Spitzer (inset).

SPIRE spectrum of part of the Orion Bar in the Orion Nebula, showing the methylidynium emission line in amongst the CO lines. Image credits: ESA/Herschel/SPIRE "Evolution of Interstellar Dust" consortium and NASA/Spitzer (inset).

A spectrum of one position on the Orion Bar, part of the Orion nebula in which the gas on the edge of the nebula is partly ionised by intense radiation from nearby hot young stars.  The inset shows a near infrared picture from NASA’s Spitzer Space Telescope.  The SPIRE spectrum has many features from CO, appearing as the dominating narrow lines, seen here for the first time together in a single spectrum.  These mean that the entire spectrum is observed at the same time and calibrated together.  The brightness of the spectral features will allow astronomers to estimate the temperature and density of interstellar gas.  The spectrum also shows the first detection of an emission feature from the molecular ion methylidynium (CH+), a key building block for larger carbon-bearing  molecules.  This and similar regions are large, and the SPIRE spectrometer’s will be extremely powerful in characterising how the gas properties vary within such sources.

SPIRE spectrum of the nearby galaxy Messier M8. Image credits: ESA/Herschel/SPIRE "Nearby Galaxies" consortium

SPIRE spectrum of the nearby galaxy Messier M8. Image credits: ESA/Herschel/SPIRE "Nearby Galaxies" consortium

The spectrum of Messier 82 (M82), a nearby galaxy (only 12 million light years away) with very active star formation.  It is part of an interacting group of galaxies including the large spiral M81.  The accompanying image (inset) is a spectacular three-colour composite picture of the two galaxies made with the SPIRE camera, showing material being stripped from M81 by the gravitational interaction with M82.  The SPIRE spectrum of M82 shows strong emission lines from CO over the whole wavelength range, as well as emission lines from atomic carbon and ionized nitrogen.

SPIRE spectrum of the galaxy Arp 220, formed by the collision of two large galaxies with inset from the Hubble Space Telescope.  Image credits: ESA/Herschel/SPIRE "Nearby Galaxies" consortium and NASA/ESA/STSci (inset).

SPIRE spectrum of the galaxy Arp 220, formed by the collision of two large galaxies with inset from the Hubble Space Telescope. Image credits: ESA/Herschel/SPIRE "Nearby Galaxies" consortium and NASA/ESA/STSci (inset).

A SPIRE spectrum of Arp 220, a galaxy 250 million light years away from Earth with very active star formation triggered when two large spiral galaxies collided to produce the complex object we see today.  Arp 220 is an important template for understanding even more distant galaxies and galaxy formation in the early universe.  The spectrum shows many emission features of CO, and H2O features are seen both in emission and absorption.  The inset is an optical image of Arp 220 made with the Hubble Space Telescope.

The SPIRE FTS observations were carried out as part of the performance verification of the observatory. The scientific rights of some of these observations are owned by Key Programme consortia:  for Arp 220 and M82, the Nearby Galaxies consortium lead by C. Wilson; for VY CMa the MESS consortium led by M. Groenewegen; for the Orion Bar, the Evolution of Interstellar Dust consortium led by A. Abergel.

Herschel and SPIRE

The European Space Agency’s Herschel satellite carries the largest telescope to be flown in space and is designed to study the Universe at far infrared wavelengths.  If successful, 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, Canada and China), led by Prof. Matt Griffin of Cardiff University.  The instrument was assembled at the STFC’s Rutherford Appleton Laboratory in the UK.

No comments
Start the ball rolling by posting a comment on this article!
Leave a reply
You must be logged in to post a comment.
© 2014 The International Space Fellowship, developed by Gabitasoft Interactive. All Rights Reserved.  Privacy Policy | Terms of Use