Z ~ 11 galaxy observed by CLASH most distant as of Nov 2012

In summary, astronomers have discovered a candidate for the most distant galaxy known to date, MACS0647-JD, with a photometric redshift of z = 10.7. It is observed as three magnified images due to strong gravitational lensing by the galaxy cluster MACSJ0647.7+7015. The galaxy is very young and only a tiny fraction of the size of our Milky Way, estimated to be less than 600 light-years wide. This suggests that it may be in the first stages of forming a larger galaxy. The discovery was made as part of the Cluster Lensing and Supernova survey with Hubble (CLASH) and was accepted for publication in the Astrophysical Journal. This find is the latest from
  • #1
marcus
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http://arxiv.org/abs/1211.3663
CLASH: Three Strongly Lensed Images of a Candidate z ~ 11 Galaxy
Dan Coe et al
(Submitted on 15 Nov 2012)
We present a candidate for the most distant galaxy known to date with a photometric redshift z = 10.7 +0.6 / -0.4 (95% confidence limits; with z < 9.5 galaxies of known types ruled out at 7.2-sigma). This J-dropout Lyman Break Galaxy, named MACS0647-JD, was discovered as part of the Cluster Lensing and Supernova survey with Hubble (CLASH). We observe three magnified images of this galaxy due to strong gravitational lensing by the galaxy cluster MACSJ0647.7+7015 at z = 0.591. The images are magnified by factors of ~8, 7, and 2,...
...This would suggest that low luminosity galaxies could have reionized the universe. However given the significant uncertainties based on only two galaxies, we cannot yet rule out the sharp drop off in number counts at z >~ 10 suggested by field searches.
Accepted for publication in the Astrophysical Journal. 23 pages, 18 figures
 
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  • #2
NASA press release about MACS0647-JD
http://www.nasa.gov/mission_pages/hubble/science/distance-record.html (dated 15 November)
Go there to see the pictures. Here's a sample of the text:
==quote==
By combining the power of NASA's Hubble and Spitzer space telescopes and one of nature's own natural "zoom lenses" in space, astronomers have set a new record for finding the most distant galaxy seen in the universe.
The newly discovered galaxy, named MACS0647-JD, is very young and only a tiny fraction of the size of our Milky Way. The object is observed 420 million years after the big bang. The inset at left shows a close-up of the young dwarf galaxy. This image is a composite taken with Hubble's WFC 3 and ACS on Oct. 5 and Nov. 29, 2011. Credit: NASA, ESA, and M. Postman and D. Coe (STScI) and CLASH Team.
The farthest galaxy appears as a diminutive blob that is only a tiny fraction of the size of our Milky Way galaxy. But it offers a peek back into a time when the universe was 3 percent of its present age of 13.7 billion years.The newly discovered galaxy, named MACS0647-JD, was observed 420 million years after the big bang, the theorized beginning of the universe. Its light has traveled 13.3 billion years to reach Earth.

This find is the latest discovery from a program that uses natural zoom lenses to reveal distant galaxies in the early universe. The Cluster Lensing And Supernova Survey with Hubble (CLASH),an international group...

MACS0647-JD is so small it may be in the first steps of forming a larger galaxy. An analysis shows the galaxy is less than 600 light-years wide. Based on observations of somewhat closer galaxies, astronomers estimate that a typical galaxy of a similar age should be about 2,000 light-years wide. For comparison, the Large Magellanic Cloud, a dwarf galaxy companion to the Milky Way, is 14,000 light-years wide. Our Milky Way is 150,000 light-years across.

"This object may be one of many building blocks of a galaxy,"said the study's lead author, Dan Coe of the Space Telescope Science Institute. "Over the next 13 billion years, it may have dozens, hundreds, or even thousands of merging events with other galaxies and galaxy fragments."

Redshift is a consequence of the expansion of space over cosmic time. Astronomers study the distant universe in near-infrared light because the expansion of space stretches ultraviolet and visible light from galaxies into infrared wavelengths. Coe estimates MACS0647-JD has a redshift of 11, the highest yet observed.
=endquote=
 
  • #3
600 light years across? That's TINY!
 
  • #4
Right! it is tiny! seems more like what we would call a "globular cluster" in size, or what people call a "proto-galaxy". It's amazing that they could see something like that at z>10.
 
  • #5
marcus said:
Right! it is tiny! seems more like what we would call a "globular cluster" in size, or what people call a "proto-galaxy". It's amazing that they could see something like that at z>10.

Yep. That's crazy!
 
  • #6
[ ]reionized the universe[ ]
Please, is there a discussion of what this means in a form where non-cosmologists can absorb it?

For example, if we have a "re"-ionized state then we must have had a prior state - maybe "de"-ionized?
 
  • #8
These very young 'galaxies' probably resemble the appearance of our own Milky Way some 500 million years after the BB.
 
  • #9
Over the next 13 billion years, it may have dozens, hundreds, or even thousands of merging events with other galaxies and galaxy fragments.
I love it when astronomers (or people proficient in the field) speak in "future tense" for things that have taken place millions of years before now.!
I'd put it "By now, the galaxy might have had dozens, hundreds, or even thousands of merging events with other galaxies and galaxy fragments"
Great discovery by the way. I'm amazed.!
 

1. What is the significance of the "Z ~ 11 galaxy observed by CLASH most distant as of Nov 2012"?

The "Z ~ 11 galaxy" refers to a galaxy with a redshift of approximately 11, meaning it is located at a distance of about 13.3 billion light years away from Earth. This makes it one of the most distant galaxies observed by the CLASH (Cluster Lensing And Supernova survey with Hubble) project as of November 2012. This discovery provides valuable insight into the early universe and the formation of galaxies.

2. How was the redshift of the "Z ~ 11 galaxy" determined?

The redshift of a galaxy is determined by measuring the shift in the wavelength of light emitted by the galaxy. As the universe expands, the wavelength of light from distant objects is stretched, resulting in a higher redshift. In the case of the "Z ~ 11 galaxy", its high redshift indicates that it is located at a significant distance from Earth.

3. What is the CLASH project and how does it observe distant galaxies?

The CLASH project is a survey conducted using the Hubble Space Telescope to study galaxy clusters and the phenomena of gravitational lensing and supernovae. By observing light from distant galaxies as it passes through these massive clusters, the CLASH project is able to gather data on the properties and evolution of these galaxies.

4. How does the discovery of the "Z ~ 11 galaxy" contribute to our understanding of the early universe?

The "Z ~ 11 galaxy" is one of the most distant galaxies observed, meaning it existed when the universe was only about 400 million years old. By studying this galaxy, scientists can gather information about the early stages of galaxy formation and the conditions of the universe at that time.

5. What are the potential implications of the discovery of the "Z ~ 11 galaxy"?

The discovery of the "Z ~ 11 galaxy" has significant implications for our understanding of the universe and its evolution. It provides evidence for the existence of galaxies in the early universe and adds to our knowledge of the processes involved in galaxy formation. This discovery also has the potential to challenge current theories and models of the early universe, leading to new discoveries and advancements in the field of cosmology.

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