Astronomers at the Gemini telescope in Hawaii have obtained a complete,
multi-dimensional picture, of the dynamic flow of gas and stars at the core
of an active galaxy [NGC 1068] located 70 million light years away. The
image was achieved in a single snapshot and is the first time such a picture
has been obtained by one of the new generation of giant telescopes with an 8
– 10 metre light collecting mirror. The astronomers used a new instrument –
the Integral Field Unit (IFU), designed and built at Durham University –
fitted to the telescope’s multi-object spectrograph to image the violent
galaxy. The resulting data has been transformed into an animation that
dramatically reveals the internal dynamics of the galaxy – including the
interactions of a pair of galactic-scale jets that spew material for
thousands of light years away from a suspected black hole at the galaxy’s
core.
“We are very excited by these results and the superb capabilities that the
IFU has added to the Gemini Multi-Object Spectrograph (GMOS)”, commented Dr.
Jeremy Allington-Smith, from Durham University, who was responsible for the
overall design and construction of the GMOS Integral Field Unit. ” 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. So far we have used it to map the motion of gas within
the nucleus of a powerful active galaxy, NGC1068, 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 instrument uses hundreds of tiny optical fibres, each thinner than a
human hair, with tiny micro-lenses attached to the end to guide light from
the telescope’s two dimensional image to a spectrograph. The spectrograph
produces one individual spectrum for each fibre, a total of 1500 individual
spectra, that can each reveal details of the physical conditions and
velocity of the gas, dust and stars that it observes. This technology is new
to the world of 8 -10 metre class telescopes and is particularly powerful
when combined with an advanced telescope like Gemini which has 10 times the
light collecting power of the Hubble Space Telescope and uses sophisticated
optical technologies to focus starlight to razor sharpness.
Dr. Gerald Cecil, of the University of North Carolina, recently studied this
particular galaxy using the Hubble Space Telescope and believes that the new
Gemini spectra 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 slit
spectrographs do. Using the Gemini Multi-Object Spectrograph’s integral
field capability allows us to perform detailed studies of the light to
provide critical physical constraints on the nature of faint cosmic
objects.” Dr. Cecil’s Hubble findings are to be published in the April 1
issue of the Astrophysical Journal.
“By using this technique we add an extra dimension to the data and can
essentially make a movie with one click of the shutter,” says Dr. Bryan
Miller, a Gemini astronomer working on Integral Field techniques. “When we
play back our movie of the galaxy NGC1068, we see a 3-dimensional view of
the core of this galaxy. It is striking how much easier it is to interpret
features with this kind of data. With 3-dimensional views of galaxies we can
determine mass distributions, true shapes, and hopefully their origins much
more accurately than before.”
“The Gemini data of NGC 1068 reveal one of the lesser known features of
galaxy jets,” explains Gemini North Associate Director Dr. Jean-Rene Roy.
“For the first time we are able to clearly see the jet’s expanding lobe as
its hypersonic bow shock slams directly into the underlying gas disk of the
galaxy. It’s like a huge wave smashing onto a cosmic shoreline.”
The IFU instrument was designed and built in the UK at Durham University.
Prof. Ian Halliday, Chief Executive of the Particle Physics and Astronomy
Research Council, the agency responsible for funding UK astronomy said, ‘
The IFU will provide astronomers with a powerful new tool to probe the
mysterious cosmic caldrons of the Universe, like those at the core of
galaxies and stellar nurseries. The UK has almost a 25% share in the twin
Gemini telescopes and it’s significant that British scientists have played
such a major role in this innovative instrument. The entire team at Durham
is to be congratulated. It clearly endorses the UK’s contribution to such
international projects.’
The Integral Field Spectroscopy capabilities of the Gemini Observatory are
still developing. Within the next two years both Gemini North on Hawaii and
its Southern Hemisphere twin in Chile will have optical and near-infrared
Integral Field Units. Some of these b;ĂŸtems will work with adaptive optics
to provide the highest spatial resolution images deliverable by the
telescopes, including images in the infrared that will be sharper than can
be produced by the Hubble Space Telescope at those wavelengths.
Images, movie, artwork and illustrations:
http://star-www.dur.ac.uk/~jra/gmos_ifu.html
http://www.gemini.edu/media/IFUImages.html
Images of Gemini North (external views of the telescope) and PPARC Chief
Executive are available on the PPARC website www.pparc.ac.uk or by
contacting Gill Ormrod in the PPARC Press Office on 01793 442012. Email:
gill.ormrod@pparc.ac.uk
For further information, contact:
Peter Barratt Head of Communications, Particle Physics and Astronomy Research Council Tel: 01793 442025 Mobile: 07879 602899 Email: peter.barratt@pparc.ac.uk Keith Seacroft Head of Public Relations Durham University Tel: 0191 374 2946 Email: keith.seacroft@durahm.ac.uk Science and Technical Dr. Jeremy Allington-Smith (after 2nd April) Durham University Tel: 0191 374 2112 Mobile: 07736 365152 Email: j.r.allington-smith@durham.ac.uk Dr Simon Morris Durham University Tel: 0191 374 4711 Email: simon.morris@durham.ac.uk Prof. Roger Davies Durham University Tel: 0191 374 2163 Email: roger.davies@durham.ac.uk Technical only Mr David Robertson Durham University Tel: 0191 374 4615 Email: d.j.robertson@durahm.ac.uk Mr Graham Murray Durham University Tel: 0191 374 2764 Email: g.j.murray@durham.ac.uk Gemini Observatory Peter Michaud Gemini Observatory, Hilo, Hawaii Tel: + 00 1 808 974 2510 Email: pmichaud@gemini.edu
Background notes
The Gemini Observatory is an international collaboration that has built two
identical 8-meter telescopes. The telescopes are located at Mauna Kea,
Hawaii (Gemini North) and Cerro Pachon in central Chile (Gemini South), and
hence provide full coverage of both hemispheres of the sky. Both telescopes
incorporate new technologies that allow large, relatively thin mirrors under
active control to collect and focus both optical and infrared radiation from
space. Gemini North began science operations in 2000 and Gemini South began
limited scientific operations in late 2001.
The Gemini Observatory provides the astronomical communities in each partner
country with state-of-the-art astronomical facilities that allocate
observing time in proportion to each country’s contribution. In addition to
financial support, each country also contributes significant scientific and
technical resources.
The national research agencies that form the Gemini partnership include:
The US National Science Foundation (NSF); The UK Particle Physics and
Astronomy Research Council (PPARC); The Canadian National Research Council
(NRC); The Chilean Comision Nacional de Investigacion Cientifica y
Tecnologica (CONICYT); The Australian Research Council (ARC); The
Argentinean Consejo Nacional de Investigaciones Cientificas y Tecnicas
(CONICET); and the Brazilian Conselho Nacional de Desenvolvimento Cientifico
e Tecnologico (CNPq). The Observatory is managed by the Association of
Universities for Research in Astronomy, Inc. (AURA), US, under a
co-operative agreement with the NSF. The NSF also serves as the executive
agency for the international partnership.
The Particle Physics and Astronomy Research Council (PPARC) is the UK’s
strategic science investment agency. It funds research, education and public
understanding in four broad areas of science – particle physics, astronomy,
cosmology and space science.
PPARC is government funded and provides research grants and studentships to
scientists in British universities, gives researchers access to world-class
facilities and funds the UK membership of international bodies such as the
European Organisation for Nuclear Research, CERN, and the European Space
Agency. It also contributes money for the UK telescopes overseas on La
Palma, Hawaii, Australia and in Chile, the UK Astronomy Technology Centre at
the Royal Observatory, Edinburgh and the MERLIN/VLBI National Facility.
PPARC’s Public Understanding of Science and Technology Awards Scheme
provides funding to both small local projects and national initiatives aimed
at improving public understanding of its areas of science.