New astronomical catalogue to become reference source

Press Release From: European Space Agency
Posted: Friday, April 4, 2003

image Monday (April 7th 2003) sees the release of one of the largest catalogues of celestial X-ray sources ever made. The result of over a year's observations by the European Space Agency's XMM-Newton space telescope, the new Serendipitous Source Catalogue locates tens of thousands of previously unknown X-ray emitting stars and galaxies. This vast catalogue will be a major resource for future research in high-energy astrophysics, for example allowing astronomers to study large numbers of galaxies with huge black holes in their centres.

Dr Mike Watson, XMM-Newton Survey Scientist, said: "XMM-Newton's X-ray mirrors have the largest collecting area ever flown, giving it impressive sensitivity to find the faintest objects in the X-ray Universe. XMM-Newton's advanced optics and instrumentation also make it possible to discover X-ray sources buried in interstellar gas and dust, which earlier satellites were not able to detect, so this new catalogue reveals many new obscured objects such as galaxies with hidden central black holes."

The data in the catalogue was collected using the EPIC X-ray cameras on the XMM-Newton observatory. These 3 cameras, all pointing in the same direction, image an area of the sky the size of the full moon. When XMM-Newton is targeted at selected astronomical objects, it also collects information on other X-ray sources, which happen to be in its field of view, providing a rich 'serendipitous' by-product of the planned observations. Each image from these cameras contains many tens of previously unknown X-ray sources.

Dr John Pye, who leads the catalogue team at Leicester, said: "This catalogue is the result of the hard work of a dedicated team, both here at the University of Leicester, at the other UK institutes involved (Mullard Space Science Laboratory - University College London, and Institute of Astronomy - Cambridge University) and at institutes in Germany, France, Spain and Italy. The catalogue already contains over 33,000 X-ray sources, but our work continues and the next version will be the largest X-ray astronomical catalogue ever made. By the end of the expected 10-year XMM-Newton mission we can expect the final catalogue to reach half a million objects."

The catalogue was made by the XMM-Newton Survey Science Centre (SSC), a European collaboration led by Dr Mike Watson at Leicester, on behalf of the European Space Agency (ESA). All XMM-Newton data is sent from the ESA Science Operations Centre near Madrid to be processed by the SSC at Leicester using computer programs developed by the SSC and ESA teams. As well as the XMM-Newton data, the catalogue incorporates the results of matching the X-ray objects with entries in a wide range of existing astronomical catalogues, using the impressive data collections provided at the Centre de Donnees astronomiques de Strasbourg. This feature of the catalogue provides a unique multi-wavelength view and a foretaste of the power of the Virtual Observatory (see below) concept. The SSC is also making observations with other, ground-based, telescopes in order to clarify the nature of some of the new X-ray sources.

The ESA Project Scientist for XMM-Newton, Dr Fred Jansen, said: "I am very pleased to see this first release of the XMM-Newton catalogue, it will be a standard reference for decades to come. The catalogue contains rich information on vast numbers of newly discovered sources of X-ray emission."

Notes for Editors

Dr Watson will announce the release of the catalogue to the astronomy community in a short presentation at the UK National Astronomy Meeting being held in Dublin on 7 - 11 April 2003.

XMM-Newton XMM-Newton was launched by the European Space Agency on the 10th of December 1999 by an Ariane V rocket from French Guiana. It is in a 48-hour orbit around the earth, faultlessly performing astronomical observations for the world's astrophysical community. XMM-Newton is the most sensitive X-ray telescope ever built. The EPIC X-ray cameras were built by a team led by Dr Martin Turner of the University of Leicester, continuing a long series of successful space X-ray instrumentation built by this group.

X-ray Astronomy X-rays are a form of electromagnetic radiation and in space they are generated by extremely hot materials (with temperatures over 1 million degrees Celsius). These sorts of temperatures occur, for example, in supernovae, stellar flares and near black holes, where the strong pull of gravity accelerates objects to very high speeds. X-rays from space are readily absorbed by the Earth's atmosphere, which means they can only be studied by launching satellites into orbit.


XMM-Newton catalogue:

XMM-Newton Survey Science Centre:

ESA XMM-Newton sites: or

International Virtual Observatory Alliance A virtual observatory is a collection of inter-operating data archives and software tools, which utilise the internet to form a scientific research environment in which astronomical research can be conducted. This allows comparisons of data from different instruments, telescopes and wavelengths to be done with ease.


XMM-Newton in orbit-

EPIC Camera


Dr Mike Watson
University of Leicester
Tel: +44 (0) 116 2523553
Fax: +44 (0) 116 252 3311
Dr Watson will be available for press contact at the National Astronomy Meeting on Tuesday April 8th and Wednesday April 9th.

Dr John Pye
University of Leicester
Tel: +44 (0) 116 2523552
Fax: +44 (0) 116 2522464

Dr Fred Jansen
ESA XMM-Newton Project Scientist
Tel: +31 (0) 71 565 4426

Julia Maddock
PPARC Press Office
Tel: +44 (0) 1793 442094

UK involvement in XMM-Newton is funded by the Particle Physics and Astronomy Research Council at a total of about 25.5 million to date, in addition to paying subscription to the European Space Agency.

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 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 Laboratory for Particle Physics (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, which includes the Lovell Telescope at Jodrell Bank observatory.

PPARC's Public Understanding of Science and Technology Awards Scheme funds both small local projects and national initiatives aimed at improving public understanding of its areas of science.

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