Hi My Friends: A VUELO DE UN QUINDE EL BLOG., With the combined power of NASA's Spitzer and Hubble space telescopes,
as well as a cosmic magnification effect, astronomers have spotted what
could be the most distant galaxy ever seen. Light from the young galaxy
captured by the orbiting observatories first shone when our
13.7-billion-year-old universe was just 500 million years old.
In the big image at left, the many galaxies of a massive cluster called MACS J1149+2223 dominate the scene. Gravitational lensing by the giant cluster brightened the light from the newfound galaxy, known as MACS 1149-JD, some 15 times. At upper right, a partial zoom-in shows MACS 1149-JD in more detail, and a deeper zoom appears to the lower right.. Image credit: NASA/ESA/STScI/JHU › Full image and caption |
NASA Telescopes Spy Ultra-Distant Galaxy Amidst Cosmic 'Dark Ages'
PASADENA, Calif. -- With the combined power of NASA's Spitzer and Hubble
space telescopes, as well as a cosmic magnification effect, astronomers
have spotted what could be the most distant galaxy ever seen. Light
from the young galaxy captured by the orbiting observatories first shone
when our 13.7-billion-year-old universe was just 500 million years old.
The far-off galaxy existed within an important era when the universe
began to transit from the so-called cosmic dark ages. During this
period, the universe went from a dark, starless expanse to a
recognizable cosmos full of galaxies. The discovery of the faint, small
galaxy opens a window onto the deepest, most remote epochs of cosmic
history.
"This galaxy is the most distant object we have ever observed with high
confidence," said Wei Zheng, a principal research scientist in the
department of physics and astronomy at Johns Hopkins University in
Baltimore who is lead author of a new paper appearing in Nature. "Future
work involving this galaxy, as well as others like it that we hope to
find, will allow us to study the universe's earliest objects and how the
dark ages ended."
Light from the primordial galaxy traveled approximately 13.2 billion
light-years before reaching NASA's telescopes. In other words, the
starlight snagged by Hubble and Spitzer left the galaxy when the
universe was just 3.6 percent of its present age. Technically speaking,
the galaxy has a redshift, or "z," of 9.6. The term redshift refers to
how much an object's light has shifted into longer wavelengths as a
result of the expansion of the universe. Astronomers use redshift to
describe cosmic distances.
Unlike previous detections of galaxy candidates in this age range, which
were only glimpsed in a single color, or waveband, this newfound galaxy
has been seen in five different wavebands. As part of the Cluster
Lensing And Supernova Survey with Hubble Program, the Hubble Space
Telescope registered the newly described, far-flung galaxy in four
visible and infrared wavelength bands. Spitzer measured it in a fifth,
longer-wavelength infrared band, placing the discovery on firmer ground.
Objects at these extreme distances are mostly beyond the detection
sensitivity of today's largest telescopes. To catch sight of these
early, distant galaxies, astronomers rely on gravitational lensing. In
this phenomenon, predicted by Albert Einstein a century ago, the gravity
of foreground objects warps and magnifies the light from background
objects. A massive galaxy cluster situated between our galaxy and the
newfound galaxy magnified the newfound galaxy's light, brightening the
remote object some 15 times and bringing it into view.
Based on the Hubble and Spitzer observations, astronomers think the
distant galaxy was less than 200 million years old when it was viewed.
It also is small and compact, containing only about 1 percent of the
Milky Way's mass. According to leading cosmological theories, the first
galaxies indeed should have started out tiny. They then progressively
merged, eventually accumulating into the sizable galaxies of the more
modern universe.
These first galaxies likely played the dominant role in the epoch of
reionization, the event that signaled the demise of the universe's dark
ages. This epoch began about 400,000 years after the Big Bang when
neutral hydrogen gas formed from cooling particles. The first luminous
stars and their host galaxies emerged a few hundred million years later.
The energy released by these earliest galaxies is thought to have
caused the neutral hydrogen strewn throughout the universe to ionize, or
lose an electron, a state that the gas has remained in since that time.
"In essence, during the epoch of reionization, the lights came on in the
universe," said paper co-author Leonidas Moustakas, a research
scientist at NASA's Jet Propulsion Laboratory, a division of the
California Institute of Technology in Pasadena, Calif.
Astronomers plan to study the rise of the first stars and galaxies and
the epoch of reionization with the successor to both Hubble and Spitzer,
NASA's James Webb Telescope, which is scheduled for launch in 2018. The
newly described distant galaxy will likely be a prime target.
For more information about Spitzer,
visit http://www.nasa.gov/spitzer .
For more information about Hubble,
visit: http://www.nasa.gov/hubble .
Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov
J.D. Harrington 202-358-5241
Headquarters, Washington
j.d.harrington@nasa.gov
NASA
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov
J.D. Harrington 202-358-5241
Headquarters, Washington
j.d.harrington@nasa.gov
NASA
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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