An international team of researchers has discovered one of the most extreme instances of magnification by gravitational lensing
Extremely distant galaxies are usually too faint to be seen, even by the largest telescopes. But nature has a solution: gravitational lensing, predicted by Albert Einstein and observed many times by astronomers. Now, an international team of astronomers, led by Harald Ebeling of the Institute for Astronomy at the University of Hawaii at Manoa, has discovered one of the most extreme instances of magnification by gravitational lensing.
The yellow dotted line traces the boundaries of the galaxy's gravitationally lensed image. The inset on the upper left shows what eMACSJ1341-QG-1 would look like if we observed it directly, without the cluster lens. The dramatic amplification and distortion caused by the intervening, massive galaxy cluster (of which only a few galaxies are seen in this zoomed-in view) is apparent.
Credit: Harald Ebelling, University of Hawaii, Institute for Astronomy.
Using the Hubble Space Telescope to survey a sample of huge clusters of galaxies, the team found a distant galaxy, eMACSJ1341-QG-1, that is magnified 30 times thanks to the distortion of space-time created by the massive galaxy cluster dubbed eMACSJ1341.9-2441.
The underlying physical effect of gravitational lensing was first confirmed during the solar eclipse of 1919, and can dramatically magnify images of distant celestial sources if a sufficiently massive object lies between the background source and observers.
Galaxy clusters, enormous concentrations of dark matter and hot gas surrounding hundreds or thousands of individual galaxies, all bound by the force of gravity, are valued by astronomers as powerful "gravitational lenses." By magnifying the galaxies situated behind them, massive clusters act as natural telescopes that allow scientists to study faint and distant sources that would otherwise be beyond the reach of even the most powerful man-made telescopes.
"The very high magnification of this image provides us with a rare opportunity to investigate the stellar populations of this distant object and, ultimately, to reconstruct its undistorted shape and properties," said team member Johan Richard of the University of Lyon, who performed the lensing calculations.
Although similarly extreme magnifications have been observed before, the discovery sets a record for the magnification of a rare "quiescent" background galaxy--one that, unlike our Milky Way, does not form new stars in giant clouds of cool gas.
Explained UH team leader Ebeling, "We specialize in finding extremely massive clusters that act as natural telescopes and have already discovered many exciting cases of gravitational lensing. This discovery stands out, though, as the huge magnification provided by eMACSJ1341 allows us to study in detail a very rare type of galaxy."
Details of the discovery are published in Astrophysical Journal Letters.
Roy Gal | EurekAlert!
Images from NJIT's big bear solar observatory peel away layers of a stellar mystery
18.11.2019 | New Jersey Institute of Technology
A one-way street for light
15.11.2019 | Rheinische Friedrich-Wilhelms-Universität Bonn
An international team of scientists, including three researchers from New Jersey Institute of Technology (NJIT), has shed new light on one of the central mysteries of solar physics: how energy from the Sun is transferred to the star's upper atmosphere, heating it to 1 million degrees Fahrenheit and higher in some regions, temperatures that are vastly hotter than the Sun's surface.
With new images from NJIT's Big Bear Solar Observatory (BBSO), the researchers have revealed in groundbreaking, granular detail what appears to be a likely...
The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...
Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.
New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...
If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.
Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...
Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...
15.11.2019 | Event News
15.11.2019 | Event News
05.11.2019 | Event News
18.11.2019 | Earth Sciences
18.11.2019 | Life Sciences
18.11.2019 | Power and Electrical Engineering