Galaxies give up their secrets
(19 July 2005)
Astronomers at Durham University are trail-blazing across the galaxies, using enormous computer power to understand how the universe developed and explain more about what it contains.
And one of their techniques is to “cook” galaxies from the ingredients of the universe and the laws of physics in the form of a computer simulation. They then compare the results with the known universe to test theories about how the universe grew.
The dramatic images figure in the latest news release from Research-tv: see www.research-tv.com/
The Durham work, seen both in flat-screen and in 3-D, are among the latest results that put the Institute of Computational Cosmology, of Durham’s Physics Department, at the heart of internationally significant space research.
Professor Carlos Frenk, Director of the Institute of Computational Cosmology, Department of Physics, Durham University, said: “This is a task that had challenged cosmologists for about a decade and we were the first to be able to successfully reproduce the milky way galaxy. It turns out that what our colleagues had been missing were some very intricate detail that we call feedback processes whereby the galaxy forming interacts with galaxies cooling down to make the stars in a fairly complicated way. This is the first time however that anybody has been able to make a galaxy that for all intents and purposes could just be the Milky Way.”
The ICC’s latest output includes:
- the largest simulation ever of the growth of the cosmos
- discovery of ‘superwinds’ spreading the dust from a vast galactic explosion 11.5 billion light years away
- identifying a new source of very high energy gamma rays
As members of the Virgo consortium, an international group of astrophysicists from the UK, Germany, Canada and the USA, the ICC has have run the largest and most realistic simulation ever of the growth of cosmic structure and the formation of galaxies and quasars. It employed more than 10 billion particles of matter to trace the evolution of the matter distribution in a section of the Universe.
In another set of observations, a Durham-led team provided the most direct evidence yet of a galaxy being almost torn apart by explosions that produce a stream of high-speed material known as "Superwinds". The observations were made using the 4.2 metre William Herschel Telescope on La Palma in which the UK is a major stakeholder. Superwinds are vital to the theory of galaxy formation. It is thought that with Superwinds galaxies blast a significant part of their gas into intergalactic space at speeds of up to several hundred miles per second. They carry heavy elements - Star dust - far from their production sites providing raw material for planets and life across the Universe.
And in another research stream, results have produced a new understanding of the universe as viewed in gamma rays, producing the first-ever gamma ray images of astronomical objects and the first scan of a large region around the centre of the galaxy. The object that is producing the high energy radiation is thought to be a 'microquasar'. These objects consist of two stars in orbit around each other. One star is an ordinary star, but the other has used up all its nuclear fuel, leaving behind a compact corpse. Depending on the mass of the star that produced it, this compact object is either a neutron star or a black hole, but either way its strong gravitational pull draws in matter from its companion star. This matter spirals down towards the neutron star or the black hole, in a similar way to water spiralling down a plughole.
Further information Web: icc.dur.ac.uk/
Professor Carlos Frenk FRS Institute for Computational Cosmology, Durham University Tel: Direct line:0191 334 3641 Secretary:0191 334 3635 e-mail: email@example.com