A New Insight into Galaxy Formation and Evolution (Forwarded)

Particle Physics and Astronomy Research Council
Swindon, U.K.

Press Contacts:

Gill Ormrod, PPARC Press Office
Tel: 01793 442 012

Eleanor Gilchrist, UK ATC Press Office
Tel: 0131 668 8397

Henri Bofffin, ESO Press Office
Tel: +49 89 3209 6222

Science Contacts:

Prof Ray Sharples, University of Durham
Tel: 0191 334 3719

Prof Roger Davies, University of Oxford
Tel: 01865 273 305

Dr Suzie Ramsay Howat, UK ATC
Tel: 0131 668 8317

Dr Malcolm Bremer, University of Bristol
Tel: 0117 928 8764

03 February 2006

A New Insight into Galaxy Formation and Evolution

Instrumentation advances over the last 10 years have allowed astronomers
to detect massive star forming galaxies in distant corners of the
universe. However, much of the precise detail about the processes that
drive galaxy formation and evolution remain elusive. This is set to
change with the development, by UK and German researchers, of a unique
infrared survey instrument for the European Southern Observatory's Very
Large Telescope (VLT) in Chile.

KMOS (K-band Infrared Multi-Object Spectrometer), will be able to
observe many galaxies simultaneously and it is the first VLT instrument
in which the UK takes a leading role employing state-of-the-art
technology to probe how the first galaxies formed and evolved. By
analyzing the spectra of these distant galaxies, using the next phase of
advanced instrumentation such as KMOS, we can determine a great deal
about their structure and history.

Prof Richard Wade, PPARC Director of Programmes and the current
President of ESO's Council, said "The leading role of UK scientists and
engineers in the design and development of KMOS presents a great
opportunity to be involved in the next phase of the development of ESO's
world class telescope facilities. Furthermore, such investment will
provide UK astronomers with increased access to the VLT -- ensuring they
remain in the forefront of scientific discoveries."

Having identified the need for a near infrared multi-object spectrometer
ESO considered competitive design studies by several European research
groups, and selected a proposal from a consortium of UK and German
institutes.

KMOS will be one of the first of a suite of second-generation
instruments being developed for the VLT. It will be built by research
groups at the Universities of Durham, Oxford, and the UK Astronomy
Technology Centre (UK ATC), together with the University Observatory
Munich and the Max Planck Institute for Extraterrestrial Physics; ESO
will provide the sensitive infrared detectors together with the control
electronics and software. Further support for the science case for the
instrument has been provided by Dr Malcolm Bremer at the University of
Bristol, building on his work already carried out using the first
generation of VLT instrumentation. Funding for the UK participation was
approved by PPARC in May 2005, and the design is now being finalized
with a preliminary design review set to take place in May 2006.

The instrument will incorporate many novel features specifically
optimized to address key questions in the formation and assembly of
galaxies. To enable surveys of statistically significant samples of
galaxies, KMOS will be able to observe up to 24 targets simultaneously,
selected from a larger field by robotic pick-off arms that relay the
light to the integral field units.

Prof Ray Sharples from the University of Durham, Principal Investigator
for KMOS, explains, "The arms must be capable of extremely reliable and
accurate positioning, and have never before been implemented in an
infrared instrument like KMOS -- making this one of the most challenging
and complex parts of the instrument."

Prof Sharples continues, "When it is delivered to the VLT in Chile in
2010, KMOS will be one of the most complex infrared instruments
operating on a ground-based telescope. It will provide UK astronomers
with one of the key tools to address some of the outstanding issues in
galaxy formation and evolution."

Notes to Editors

In order to deal with the complex shapes and multiple components of
forming galaxies, KMOS will use the new technique of integral field
spectroscopy in which the light from every point in the image of a
galaxy is dispersed in wavelength to produce a spectrum. The data are
then reassembled into a 'data cube' with two spatial coordinates and one
spectral (wavelength or velocity) dimension. KMOS will use a technique
known as image-slicing to produce the data cubes. This relies on novel
manufacturing methods based on precision diamond-machined optics
pioneered in the UK.

In order see the most distant galaxies as they formed, KMOS will observe
in the near infrared part of the spectrum between 1.0 and 2.4
micrometres wavelength. As this is the part of the spectrum dominated by
the heat radiation from warm bodies, the entire KMOS instrument will
have to be cooled to cryogenic temperatures (-150 C).

Role of UK Institutions in KMOS

The KMOS construction project is divided into a number of separate work
packages which are divided between the different institutes in the
consortium. The main work package responsibilities for the UK
institutions a

The University of Durham is responsible for providing the front-end
pickoff module for KMOS including procurement of the 24 pickoff arms,
manufacture of the integral field units and design of the calibration unit.

The University of Oxford is responsible for providing the 3 back-end
unit spectrographs which disperse the light into its constituent
wavelengths within KMOS, using optical design work carried out at
Rutherford Appleton Laboratory. Prof Roger Davies will use KMOS to
explore galaxy evolution and measure masses of galaxies when they were
only half of their current age (7 million years ago) in order to
determine how galaxies have assembled over cosmic time. KMOS will also
be used to look even further back in time when the first galaxies were
forming.

The UK ATC provides overall project management and systems engineering
for KMOS and will host the assembly, integration and test phase prior to
KMOS shipping to Chile, under the direction of the Instrument Scientist
Dr Suzie Ramsay Howat. In addition, UK ATC is responsible for the design
of the robotic pickoff arms and will test the first prototype this year.
The cryostat and infrastructure which will be used to cool KMOS to
cryogenic temperatures and the detector mount are also being designed in
Edinburgh.

Dr Malcolm Bremer from the University of Bristol has been primarily
involved in forming the scientific case for the instrument through his
work on high redshift clusters of galaxies and observations of the most
distant galaxies. Questions and issues arising from his work on these
topics using the current first generation of ESO instrumentation has
helped shape the capabilities of KMOS so that it can make real advances
in the understanding of galaxy formation and evolution.

Images relating to the design of KMOS,
http://www.pparc.ac.uk/Nw/KMOS_images.asp

ESO is the European Organisation for Astronomical Research in the
Southern Hemisphere. Whilst the headquarters (comprising the scientific,
technical and administrative centre of the organization) are located in
Garching near Munich, Germany, ESO operates three observational sites in
the Chilean Atacama desert. The Very Large Telescope (VLT), is located
on Paranal, a 2,600m high mountain south of Antofagasta. At La Silla,
600 km north of Santiago de Chile at 2,400 m altitude, ESO operates
several medium sized optical telescopes. The third site is the 5,000 m
high Llano de Chajnantor, near San Pedro de Atacama. Here a new
submillimetre telescope (APEX) is in operation, and a giant array of 12
m submillimetre antennas (ALMA) is under development. Over 1600
proposals are made each year for the use of the ESO telescopes.

About PPARC,
http://www.pparc.ac.uk/Ap/intro.asp