Posted on 05/05/2015 10:50:45 AM PDT by Red Badger
An international team of astronomers led by Yale University and the University of California-Santa Cruz have pushed back the cosmic frontier of galaxy exploration to a time when the universe was only 5% of its present age.
The team discovered an exceptionally luminous galaxy more than 13 billion years in the past and determined its exact distance from Earth using the powerful MOSFIRE instrument on the W.M. Keck Observatory's 10-meter telescope, in Hawaii. It is the most distant galaxy currently measured.
The galaxy, EGS-zs8-1, was originally identified based on its particular colors in images from NASA's Hubble and Spitzer space telescopes. It is one of the brightest and most massive objects in the early universe.
Age and distance are vitally connected in any discussion of the universe. The light we see from our Sun takes just eight minutes to reach us, while the light from distant galaxies we see via today's advanced telescopes travels for billions of years before it reaches us—so we're seeing what those galaxies looked like billions of years ago.
"It has already built more than 15% of the mass of our own Milky Way today," said Pascal Oesch, a Yale astronomer and lead author of a study published online May 5 in Astrophysical Journal Letters. "But it had only 670 million years to do so. The universe was still very young then." The new distance measurement also enabled the astronomers to determine that EGS-zs8-1 is still forming stars rapidly, about 80 times faster than our galaxy.
Only a handful of galaxies currently have accurate distances measured in this very early universe. "Every confirmation adds another piece to the puzzle of how the first generations of galaxies formed in the early universe," said Pieter van Dokkum, the Sol Goldman Family Professor of Astronomy and chair of Yale's Department of Astronomy, who is second author of the study. "Only the largest telescopes are powerful enough to reach to these large distances."
The MOSFIRE instrument allows astronomers to efficiently study several galaxies at the same time. Measuring galaxies at extreme distances and characterizing their properties will be a major goal of astronomy over the next decade, the researchers said.
The new observations establish EGS-zs8-1 at a time when the universe was undergoing an important change: The hydrogen between galaxies was transitioning from a neutral state to an ionized state. "It appears that the young stars in the early galaxies like EGS-zs8-1 were the main drivers for this transition, called reionization," said Rychard Bouwens of the Leiden Observatory, co-author of the study.
Taken together, the new Keck Observatory, Hubble, and Spitzer observations also pose new questions. They confirm that massive galaxies already existed early in the history of the universe, but they also show that those galaxies had very different physical properties from what is seen around us today. Astronomers now have strong evidence that the peculiar colors of early galaxies—seen in the Spitzer images—originate from a rapid formation of massive, young stars, which interacted with the primordial gas in these galaxies.
The observations underscore the exciting discoveries that are possible when NASA's James Webb Space Telescope is launched in 2018, note the researchers. In addition to pushing the cosmic frontier to even earlier times, the telescope will be able to dissect the galaxy light of EGS-zs8-1 seen with the Spitzer telescope and provide astronomers with more detailed insights into its gas properties.
"Our current observations indicate that it will be very easy to measure accurate distances to these distant galaxies in the future with the James Webb Space Telescope," said co-author Garth Illingworth of the University of California-Santa Cruz. "The result of JWST's upcoming measurements will provide a much more complete picture of the formation of galaxies at the cosmic dawn."
Journal reference: Astrophysical Journal Letters
The galaxy EGS-zs8-1 sets a new distance record. It was discovered in images from the Hubble Space Telescope's CANDELS survey. Credit: NASA, ESA, P. Oesch and I. Momcheva (Yale University), and the 3D-HST and HUDF09/XDF teams
Now there’s a question to ponder....but definately not if you’re stoned.
...not so sure now. One article (excerpt just below) says the galaxy has a redshift of 7.7. While your NASA link for the gamma-ray burst claims a redshift of 8.2 for the GRB. That of course WOULD make it further than the galaxy.
“NASA’s Spitzer Space Telescope also observed the unique galaxy. The W. M. Keck Observatory was used to obtain a spectroscopic redshift (z=7.7), extending the previous redshift record.”
http://astronomynow.com/2015/05/05/astronomers-set-a-new-galaxy-distance-record/
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“The [gamma-ray] burst occurred at 3:55 a.m. EDT on April 23rd. Swift quickly pinpointed the explosion, allowing telescopes on Earth to target the burst before its afterglow faded away. Astronomers working in Chile and the Canary Islands independently measured the explosion’s redshift. It was 8.2, smashing the previous record of 6.7 set by an explosion in September 2008. A redshift of 8.2 corresponds to a distance of 13.035 billion light years.
http://science.nasa.gov/science-news/science-at-nasa/2009/28apr_grbsmash/
According to Wiki, it’s 13.095 LY away................
http://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects#cite_note-Tanvir2009-2
I think about that and it drives me nuts. Too bizarre to know, above all our pay grades.
No edge, according to the astronomers/cosmologists. And there is no *one* center of the universe. Again, according to the pros, EVERYWHERE is the center. No matter where you are in the universe, everything else appears to be expanding away from you. So if the universe has no center, it can have no edge. Makes sense? If it does, please explain it to me!! :)
“If there is a bright center to the universe, you’re on the planet that it’s farthest from” - Luke S.
I don’t think so. That would mean the galaxies were expanding away from each other at 99.99999% of the speed of light just barely keeping ahead of the light until it caught up with us after 13 billion years.
The light we are seeing left that galaxy 13 billion years ago. If the galaxies are all expanding, as they say they are, then it is a lot further than 13 billion light years away right now.
Even one billion is such a big number that we need a useful frame of reference in order to grasp it. The best of which I'm aware is this: our hearts beat one billion times in about thirty years. So I'm at about 2.2 billion beats. Since you asked, thought I'd share.
I don’t know the answer right now. I will look into it some more when my brain is working better. Because I do now recall that it is not as straight forward as it might seem at first.
For example...
3.1 Redshift velocity and recessional velocity
3.1.1 Redshift velocity
3.1.2 Recessional velocity
3.2 Observability of parameters
3.3 Expansion velocity vs relative velocity
3.4 Idealized Hubble’s Law
3.5 Ultimate fate and age of the universe
3.6 Olbers’ paradox
3.7 Dimensionless Hubble parameter
http://en.wikipedia.org/wiki/Hubble%27s_law
No, there’s nothing straightforward about it at all. It’s a real mind bender.
The light from EGS-zs8-1 that we see now has traveled a more or less straight line from where it was 13 billion years ago to where we are now. So when we look at that from here we are seeing its position, from here, 13b years ago.
But EGS-zs8-1 has had 13 billion years to move from that position just as the Milky Way had 13 billion years to move from where it was then to where we are now.
Or so it would seem to me.
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