NASA's Hubble Space Telescope has photographed an unusual structure 100,000 light years long, which resembles a corkscrew-shaped string of pearls and winds around the cores of two colliding galaxies.
The unique structure of the star spiral may yield new insights into the formation of stellar superclusters that result from merging galaxies and gas dynamics in this rarely seen process.
"We were surprised to find this stunning morphology. We've long known that the 'beads on a string' phenomenon is seen in the arms of spiral galaxies and in tidal bridges between interacting galaxies. However, this particular supercluster arrangement has never been seen before in giant merging elliptical galaxies," said Grant Tremblay of the European Southern Observatory in Garching, Germany.
Young, blue super star clusters are evenly spaced along the chain through the galaxies at separations of 3,000 light-years. The pair of elliptical galaxies is embedded deep inside the dense galaxy cluster known as SDSS J1531+3414. The cluster's powerful gravity warps the images of background galaxies into blue streaks and arcs that give the illusion of being inside the cluster, an effect known as gravitational lensing.
Observing astronomers first hypothesized that the "string of pearls" was actually a lensed image from one of these background galaxies, but their recent follow-up observations with the Nordic Optical Telescope in Santa Cruz de Tenerife, Spain, ruled out this hypothesis.
The galaxy cluster is part of a Hubble program to observe 23 massive clusters that create powerful gravitational lensing effects on the sky. The clusters were first cataloged in the Sloan Digital Sky Survey (SDSS), a project to create the most detailed three-dimensional maps ever made of the universe.
Tremblay's team discovered the bizarre string of stellar superclusters by chance, while reviewing images as they came in from Hubble. Researchers were stunned by what they saw in SDSS J1531+3414, and the unique nature of the source spurred the team to do follow-up observations with both ground and space-based telescopes.
The underlying physical processes that give rise to the "string of pearls" structure are related to the Jeans instability, a physics phenomenon that occurs when the internal pressure of an interstellar gas cloud is not strong enough to prevent gravitational collapse of a region filled with matter, resulting in star formation. This process is analogous to that which causes a column of water falling from a rain cloud to disrupt, and rain to fall in drops rather than in continuous streams.
Scientists currently are working on a better understanding of the star chain's origin. One possibility is that the cold molecular gas fueling the burst of star formation may have been native to the two merging galaxies. Another possibility is a so-called "cooling flow" scenario, where gas cools from the ultra-hot atmosphere of plasma that surrounds the galaxies, forming pools of cold molecular gas that starts to form stars. The third possibility is that the cold gas fueling the chain of star formation originates from a high-temperature shock wave created when the two giant elliptical galaxies crash together. This collision compresses the gas and creates a sheet of dense cooling plasma.
"Whatever the origin for this star-forming gas is, the result is awesome. It's very exciting. You can't find a mundane explanation for this," Tremblay said.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.
For images and more information about Hubble, visit:
To learn more about gravitational lensing, visit:
Ray Villard | Eurek Alert!
Nanotechnology for energy materials: Electrodes like leaf veins
27.09.2016 | Helmholtz-Zentrum Berlin für Materialien und Energie GmbH
First quantum photonic circuit with electrically driven light source
27.09.2016 | Westfälische Wilhelms-Universität Münster
Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.
Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...
Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.
Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...
The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...
With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...
For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.
Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...
28.09.2016 | Event News
27.09.2016 | Event News
23.09.2016 | Event News
28.09.2016 | Medical Engineering
28.09.2016 | Materials Sciences
28.09.2016 | Business and Finance