Hubble captures massive dead disc galaxy
By combining the power of a “natural lens” into space with the capability of NASA’s Hubble Space Telescope, astronomers have made a startling discovery: the first example of a compact but massive galaxy, rapid, disk-shaped rotation , Which stopped making stars only a few billion years after the big bang.
Finding a galaxy so early history of the universe challenges the current understanding of how massive galaxies form and evolve, according to the researchers.
When Hubble photographed the galaxy, astronomers expected to see a chaotic ball of stars formed by fused galaxies. Instead, they saw evidence that stars are born on a pancake-shaped disk.
This is the first evidence of direct observation that at least some of the first galaxies called “dead” – where star formation somehow left – change from a Milky Way disk like the giant elliptical galaxies we see today .
It is a surprise because elliptical galaxies contain older stars, while spiral galaxies typically contain young blue stars.
At least some of these “dead” raw disk galaxies must have gone through great achievements.
They not only change their structure, but also the movements of their stars to form the shape of an elliptical galaxy.
“This new vision may force us to rethink the cosmological context of how galaxies burn soon and become local elliptical form galaxies,” said study leader Sune Toft of the Cosmology Center at the Dark Institute Niels Bohr of the University of Copenhagen, Denmark.
“Perhaps we have been blind to the fact that the first” dead “galaxies could actually be disks, simply because we could not solve them.
As a “natural telescope” in space, the MACS gravity in the extremely close-up extremely massive post J2129-0741, illuminates and distorts the galaxy very MACS2129-1 now, shown in the top box.
The center frame is an exploded view of the galaxy lens. In the lower frame, a reconstructed image based on the modeling, shows the galaxy would look as if the group of galaxies was not present.
The galaxy looks red because it is so distant that its light shifts to the red part of the spectrum.
Previous studies of distant dead galaxies have assumed that their structure is similar to evolving local ellipticals. Confirming this in principle requires more powerful space telescopes than currently available.
However, through the phenomenon known as the “gravitational lens,” a massive group of galaxies in the foreground acts as an “Optical Zoom” natural space by expanding and stretching background images of much more distant galaxies.
By joining this natural lens with Hubble’s resolving power, scientists were able to see in the center of the galaxy dead.
The remote galaxy is three times larger than the Milky Way, but only half the size. Measurements of speed achieved with the European Southern Observatory’s Very Large Telescope (VLT) showed that the disc of the galaxy is more than twice as fast as the Milky Way.
Using data from the Cluster Shooting Cluster and the Hubble Supernova Survey (CLASH), Toft and his team identified stellar mass, star formation rate, and age of stars.
Why this galaxy has stopped the formation of stars is still unknown. This may be the result of an active galactic nucleus, where the energy springs a black hole.
This energy inhibits the qualification of the formation by heating of the gas or the expulsion of the galaxy.
Or perhaps the result of the fact that the cold gas flow to the galaxy is rapidly compressing and heating up, which prevents clouds from forming in the center of the galaxy.