* Astronomy

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RE: UDFj-39546284

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Title: Confirmation of the z~10 Candidate UDFj-39546284 using deeper WFC3/IR+ACS+IRAC Observations over the HUDF09/XDF
Authors: R. J. Bouwens (Leiden), P. A. Oesch (UCSC), G. D. Illingworth (UCSC), I. Labbe (Leiden), D. Magee (UCSC), R. Smit (Leiden), M. Franx (Leiden), P. G. van Dokkum (Yale), M. Trenti (Cambridge), V. Gonzalez (UCR), C. M. Carollo (ETH)

Ultra-deep WFC3/IR observations on the Hubble Ultra Deep Field from the HUDF09 program revealed just one probable z~10 candidate UDFj-39546284. UDFj-39546284 had all the properties one might expect of a galaxy at z~10. Not only did the candidate show no detection in any ultra-deep imaging data blueward of the F160W band, but the candidate exhibited a very blue spectral slope redward of the break, showing no prominent detection in the IRAC observations. The chief concern about this candidate was that it was a 5.9sigma single-band detection and therefore had a small chance of being spurious. Using new, deep WFC3/IR F160W observations over the HUDF09/XDF field, we test the reality of this candidate. We find that UDFj-39546284 is detected at 4.3sigma in the new observations, and at 7.1sigma in the full 77-orbit H_160-band image. This demonstrates at >99.99% confidence that this z~10 candidate corresponds to a real source. We strengthen the z~10 candidate detection even further by taking advantage of an even deeper stack of optical XDF observations over the HUDF and with 120-hour IRAC IUDF10 observations to place even tighter constraints on its probable redshift. For flat priors, we find that the source is 97% likely to be at redshift greater than 8. The full H_160-band stack also provides information on the morphology of the source. The source appears to consist of a bright core embedded in a larger structure extending to 0.4" (1.6 kpc physical).

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Santa Cruz Astronomer Discovers Ancient Galaxy

University of California at Santa Cruz astronomy professor Garth Illingworth spent the better part of two years looking at a tiny patch of sky before he saw something no one has seen before.
It was a new galaxy, not just far away, but as many as 13.2 billion years old - that is, literally, he was looking at something that was happening billions of years ago.
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Hubble telescope detects the oldest known galaxy

It is thought the galaxy is more than 13 billion years old and existed 480 million years after the Big Bang.
A Nasa team says this was a period when galaxy formation in the early Universe was going into "overdrive".
The image, which has been published in Nature journal, was detected using Hubble's recently installed wide field camera.
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Title: A candidate redshift z ~ 10 galaxy and rapid changes in that population at an age of 500 Myr
Authors: R.J. Bouwens (UC Santa Cruz, Leiden), G.D. Illingworth (UC Santa Cruz), I. Labbe (Carnegie Observatories), P.A. Oesch (ETH Zurich), M. Carollo (ETH Zurich), M. Trenti (U Colorado), P.G. van Dokkum (Yale), M. Franx (Leiden), M. Stiavelli (STScI), V. Gonzalez (UC Santa Cruz), D. Magee (UC Santa Cruz)
(Version, v5)

Searches for very-high-redshift galaxies over the past decade have yielded a large sample of more than 6,000 galaxies existing just 900-2,000 million years (Myr) after the Big Bang (redshifts 6 > z > 3; ref. 1). The Hubble Ultra Deep Field (HUDF09) data have yielded the first reliable detections of z ~ 8 galaxies that, together with reports of a gamma-ray burst at z ~ 8.2 (refs 10, 11), constitute the earliest objects reliably reported to date. Observations of z ~ 7-8 galaxies suggest substantial star formation at z > 9-10. Here we use the full two-year HUDF09 data to conduct an ultra-deep search for z ~ 10 galaxies in the heart of the reionisation epoch, only 500 Myr after the Big Bang. Not only do we find one possible z ~ 10 galaxy candidate, but we show that, regardless of source detections, the star formation rate density is much smaller (~10%) at this time than it is just ~200 Myr later at z ~ 8. This demonstrates how rapid galaxy build-up was at z ~ 10, as galaxies increased in both luminosity density and volume density from z ~ 8 to z ~ 10. The 100-200 Myr before z ~ 10 is clearly a crucial phase in the assembly of the earliest galaxies.

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NASA's Hubble Finds Most Distant Galaxy Candidate Ever Seen in Universe

Astronomers have pushed NASA's Hubble Space Telescope to its limits by finding what is likely to be the most distant object ever seen in the universe. The object's light travelled 13.2 billion years to reach Hubble, roughly 150 million years longer than the previous record holder. The age of the universe is approximately 13.7 billion years.
The tiny, dim object is a compact galaxy of blue stars that existed 480 million years after the big bang. More than 100 such mini-galaxies would be needed to make up our Milky Way. The new research offers surprising evidence that the rate of star birth in the early universe grew dramatically, increasing by about a factor of 10 from 480 million years to 650 million years after the big bang.
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