Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UK astronomers use Hubble’s most sensitive image of the Universe to find extremely distant star forming galaxies

24.09.2004


The recently released Hubble Space Telescope Ultra Deep Field (HUDF) - the most sensitive image of the distant universe ever obtained - has provided UK astronomers with a window on star formation when the universe was young, revealing some of the earliest star forming galaxies yet detected.

The research was led by Dr Andrew Bunker at the University of Exeter and graduate student Elizabeth Stanway at the Institute of Astronomy at Cambridge University. Their results have been accepted for publication in the journal ’Monthly Notices of the Royal Astronomical Society’.

This UK team was the first to analyse the Ultra Deep Field images, generating their results within a day of the data becoming available. Their work has been confirmed by other groups researching in the field, and is the subject of a NASA press conference at the Space Telescope Science Institute, Baltimore today (23 September 2004).



Bunker and colleagues identified fifty objects likely to be galaxies from the HUDF data that looked 95 per cent of the way back to the beginning of the Universe. The redshifts of these galaxies are about 6 - so far away that light from them has taken 13 billion years to reach us. This is more than twice the age of our Solar System, and the galaxies which the UK team have discovered existed when the universe was less than a billion years old. "Intervening gas clouds absorbed visible light from these galaxies long before it reached Earth, but their infrared light can be detected," explained Elizabeth Stanway, "and it is their infrared colours which lead us to believe that these galaxies lie at such immense distances."

The astronomers turned to two of the largest telescopes in the world, the 10-metre Keck telescope, in Hawaii, and the 8-metre Gemini telescope in Chile to verify their findings with spectroscopic techniques. In some of these spectra they saw the hydrogen gas glowing as it was illuminated by hot, newly-born stars. "These galaxies are in the process of giving birth to stars - each year they convert a mass of gas more than that of our sun into new stars," said Professor Richard Ellis of the California Institute of Technology.

"Using the largest optical telescope, Keck, was very important as it showed that this population of objects discovered by the Hubble Space Telescope really are incredibly distant", added Andrew Bunker, who was also part of the team which did the observing in Hawaii.
But these discoveries pose a cosmic puzzle: on the basis of their sample, the UK team can calculate how fast stars are being born in distant galaxies at redshift 6. They have compared the answer with previous work looking at nearer galaxies, with redshifts around 3. "It seems that there are fewer of these galaxies early in the history of the Universe at redshift 6, compared to more recent times," said Andrew Bunker.

Richard McMahon, another of the Cambridge team, explained the importance of exploring these high redshifts: "At this early time in the history of the universe, a major phase change occurred. The space between galaxies was filled with largely neutral gas, but suddenly this was ionised - forming a plasma." The main candidate for what caused this is ultraviolet radiation, which can be generated as stars are born. Yet, the small number of star forming galaxies found in the Ultra Deep Field may not be sufficient to do this.

It is possible that the first stars and galaxies were born at even earlier times, and this will be explored by the successor to Hubble, the James Webb Space Telescope, which will operate in the infrared.

Julia Maddock | alfa
Further information:
http://www.pparc.ac.uk

More articles from Physics and Astronomy:

nachricht Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

nachricht What do Netflix, Google and planetary systems have in common?
02.12.2016 | University of Toronto

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>