Space

July 11, 2014

Hubble spots spiral bridge of young stars linking two ancient galaxies

NASA’s Hubble Space Telescope photographed a 100,000-light-year-long structure that looks like a string of pearls twisted into a corkscrew shape winds around the cores of the two massive galaxies. The ìpearlsî are superclusters of blazing, blue-white, newly born stars.

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, D.C.




All of this week's top headlines to your email every Friday.


 
 

 

Headlines December 17, 2014

News: U.S. Air Force tanker platform slated for year-end debut - Boeing is planning for first flight of its 767-2C – upon which the U.S. Air Force’s new KC-46 tanker will be based – by year’s end, six months late. Northrop Grumman wins $657.4 million deal to supply drones to South Korea - Northrop Grumman has won...
 
 

NASA launches new Micro-g NExT for undergraduates

NASA is offering undergraduate students an opportunity to participate in a new microgravity activity called Micro-g Neutral Buoyancy Experiment Design Teams. The deadline for proposals is Jan. 28, 2015. Micro-g NExT challenges students to work in teams to design and build prototypes of spacewalking tools to be used by astronauts for spacewalk training in the...
 
 
launch1

Storm fails to quench liftoff of secret reconnaissance satellite

The fiery launch of an Atlas V (541), among the most powerful of the venerable Atlas family, briefly dispelled the gloom over Californiaís Central Coast on the evening of Dec. 12. A team of personnel from United Launch Allianc...
 

 
Coast Guard photograph

Navy demonstrates unmanned helicopter operations aboard Coast Guard cutter

http://static.dvidshub.net/media/video/1412/DOD_102145893/DOD_102145893-512×288-442k.mp4 Coast Guard photograph An MQ-8B Fire Scout UAS is tested off the Coast Guard Cutter Bertholf near Los Angeles, Dec. 5 2014. The Coast...
 
 
GPS-OCX

GPS III, OCX successfully demonstrate key satellite command, control capabilities

Lockheed Martin and Raytheon successfully completed the fourth of five planned launch and early orbit exercises to demonstrate new automation capabilities, information assurance and launch readiness of the worldís most powerfu...
 
 

Aerojet Rocketdyne successfully demonstrates 3D printed rocket propulsion system for satellites

Aerojet Rocketdyne has successfully completed a hot-fire test of its MPS-120 CubeSat High-Impulse Adaptable Modular Propulsion System. The MPS-120 is the first 3D-printed hydrazine integrated propulsion system and is designed to provide propulsion for CubeSats, enabling missions not previously available to these tiny satellites. The project was funded out of the NASA Office of Chief...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>