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Friday, 22 March, 2002, 13:21 GMT
Violent galaxy seen in 3D
NGC 1068, PParc
Artist's impression of the violent jet motions in galaxy NGC 1068
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By Dr David Whitehouse
BBC News Online science editor
line
Astronomers using the Gemini North telescope in Hawaii have obtained a three-dimensional picture of the flow of gas and stars at the violent centre of an active galaxy.


This technique... can essentially make a movie with one click of the shutter

Dr Bryan Miller, Gemini astronomer
The scientists used a new instrument - the Integral Field Unit (IFU), designed and built at Durham University, UK.

The data reveal the internal dynamics of the galaxy and show huge pair of jets hurling material thousands of light-years away from what is probably a black hole at the core.

"We are very excited by these results and the superb capabilities that the IFU has added to the Gemini telescope," said Dr Jeremy Allington-Smith, from Durham.

Extra dimension

"In effect we have added an extra dimension to the main instrument so that it can physically map the motion of gas and stars at any point in the image of the object under study," he added.

Gemini North, PParc
Gemini North recently opened for business
"So far we, have used it to map the motion of gas within the nucleus of a powerful active galaxy, NGC 1068, and the orbits of stars within more normal galaxies, but it can also be used to study regions within our own galaxy where stars are being formed."

The IFU uses hundreds of tiny optical fibres, each thinner than a human hair, with tiny micro-lenses that guide light from the telescope's image into a spectrograph where it is analysed.

The spectrograph produces one individual spectrum for each fibre - a total of 1,500 individual spectra for the entire image. The data can reveal details of the physical conditions and velocity of the gas, dust and stars.

Cosmic shoreline

Dr Gerald Cecil, of the University of North Carolina, US, recently studied this particular galaxy using the Hubble Space Telescope and believes that the new Gemini image will clarify many patterns revealed by Hubble.

"Large ground-based telescopes like Gemini are the perfect compliment to Hubble because they can collect so much more light. But it's critical to use all this light cunningly, and not throw most of it away as standard spectrographs do.

Gemini astronomer Dr Bryan Miller added: "By using this technique we add an extra dimension to the data and can essentially make a movie with one click of the shutter."

And Gemini North Associate Director Dr Jean-Rene Roy explained: "The Gemini data of NGC 1068 reveal one of the lesser known features of galaxy jets.

"For the first time, we are able to clearly see the jets' expanding lobe as its hypersonic bow shock slams directly into the underlying gas disc of the galaxy. It's like a huge wave smashing on to a cosmic shoreline."

NGC 1068, PParc
How the data is collected on NGC 1068
See also:

18 Jan 02 | Sci/Tech
Gemini opens its eyes
28 Jun 99 | Sci/Tech
Gemini images rival space telescope
22 Mar 02 | Sci/Tech
Telescope snaps 'perfect spiral'
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