Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Lenses galore - Hubble finds large sample of very distant galaxies

By using the gravitational magnification from six massive lensing galaxy clusters, the NASA/ESA Hubble Space Telescope has provided scientists with the largest sample of very distant galaxies seen to date.

Some of the newly found magnified objects are dimmer than the faintest ones seen in the legendary Hubble Ultra Deep Field, which is usually considered the deepest image of the Universe.

By combining both visible and near-infrared observations from Hubble’s Advanced Camera for Surveys (ACS) and Near Infrared Camera and Multi-Object Spectrometer (NICMOS), scientists searched for galaxies that are only visible in near-infrared light. They uncovered 10 candidates believed to lie about 13 billion light-years away (a redshift of approximately 7.5), which means that the light gathered was emitted by the stars when the Universe was still very young — a mere 700 million years old.

“These candidates could well explain one of the big puzzles plaguing astronomy today. We know that the Universe was reionised within the first 5-600 million years after the Big Bang, but we don’t know if the ionising energy came from a smaller number of big galaxies or a more plentiful population of tiny ones”, said Johan Richard, from the California Institute of Technology. The relatively high number of redshift 7.5 galaxies claimed in this survey suggests that most of the ionising energy was produced by dim and abundant galaxies rather than large, scarce ones.

“The challenge for astronomers is that galaxies beyond a distance of 13 billion light-years (past a redshift of 7) are exceedingly faint and are only visible in the near-infrared — just at the limit of what Hubble can observe” explained Jean-Paul Kneib from the Laboratoire d’astrophysique de Marseille. This new result was only made possible with some cosmic assistance in the form of gravitational lensing that magnified the light from the distant galaxies enough for Hubble to detect them. A firm confirmation of their distance was beyond even the capabilities of the 10-meter Keck telescope and must await powerful future ground-based telescopes.

First confirmed in 1979, gravitational lenses were predicted by Albert Einstein’s theory of General Relativity, a theory that allows astronomers to calculate the path of starlight as it moves through curved space-time. According to the theory, the bending of light is brought about by the presence of matter in the Universe, which causes the fabric of space-time to warp and curve.

Gravitational lensing is the result of this warping of spacetime and is mainly detected around very massive galaxy clusters. Due to the gravitational effect of both the cluster’s observable matter and hidden dark matter, the light is bent around the cluster. This bending of light allows the clusters in certain places to act as natural gravitational telescopes that give the light of faint and faraway objects a boost.

Where Earth-bound telescopes fail to detect such faint and distant objects due to the blurring introduced by the Earth’s atmosphere, a combination of Hubble’s location in space and the magnification of the gravitation lenses provides astronomers with a birds-eye view of these elusive objects.

This technique has already been used numerous times by Hubble and has helped astronomers to find and study many of the most distant known galaxies.

Lars Christensen | alfa
Further information:

More articles from Physics and Astronomy:

nachricht OU-led team discovers rare, newborn tri-star system using ALMA
27.10.2016 | University of Oklahoma

nachricht First results of NSTX-U research operations
26.10.2016 | DOE/Princeton Plasma Physics Laboratory

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: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>