Near the end of October, the astronomical findings of Matt Lehnert of the Observatoire de Paris and his group of researchers were published in Nature magazine, presenting evidence that one dim pinpoint of light observable from an image taken from the Hubble Telescope’s Wide Field Camera 3 was the most distant galaxy yet identified. Not only was the galaxy the farthest away from Earth than any other known entity, it also, by rule that light seen is past light produced, became the youngest galaxy known. It is discoveries such as this that lend a strange credence to the words: “A long time ago, in a galaxy far, far away…”
The young and distant galaxy, dubbed UDFy-38135539, was nearly missed when researchers perused the snapshot of the universe captured in the Hubble Deep Field imagery. If not from light from nearby galaxies, it might have gone unnoticed. UDFy-38135539 is so distant it is 600 million years young, a mere child of the universe and barely into the space clearing stage known as reionization, where stars drain the hydrogen from the areas around them, leaving the expanse of space.
But is UDFy-38135539 really the farthest galaxy, or will there come a time when another research team announces a more distant cluster of stars, an even younger galaxy?
“Measuring the redshift of the most distant galaxy so far is very exciting in itself, but the astrophysical implications of this detection are even more important,” Nicole Nesvadba of France’s Institute d’Astrophysique Spatiale was quoted in MSNBC’s “Cosmic Log.” “This is the first time we know for sure that we are looking at one of the galaxies that cleared out the fog which had filled the very early universe.”
Nesvadba notes that UDFy-38135539’s redshift reveals that it is “one of the galaxies” of a younger universe, suggesting that the relatively young galaxy is merely the latest youngest and not the last youngest galaxy that will be found. And there is ample precedent for such a hopefully leading statement. Appropriately enough, one has to travel back chronologically to earlier discoveries to note that the youngest galaxy revealed by researchers was not always UDFy-38135539.
A gamma ray burst detected by NASA/STFC/ASI Swift satellite in April 2009 was presented by the European Southern Observatory as the farthest known object in the universe in Nature magazine in August of the same year. The gamma burst, named GRB 090423, is marginally older than UDFy-38135539 and, according to CNN, is evidence of a supernova explosion in a galaxy formed around the same general time. The difference in age is calculated by the redshift factor (the movement of light away from an object). GRB 090423 was discovered in the Leo constellation.
In 2008, the Hubble Space Telescope offered up images that led to the discovery of A1689-zD1. Thirteen billion light years away, that then youngest discovered galaxy was estimated to be 700 million old. According to Space.com, A1689-zD1 was found when researchers at European Southern Observatory noticed that the light around galaxy cluster Abell 1689 was acting as a magnifier (due to its immense gravitational pull, Abell 1689 was bending the light around it, producing a magnification effect), which then led to finding A1689-zD1.
The European Southern Observatory find left room for still younger discoveries. Even the title of the Space.com article suggested such: “Fathest Galaxy Found, Perhaps.”
And now there is evidence again of yet another youngest, farthest galaxy.
As technology improves the detection and imaging techniques of the Hubble Telescope and any future observation mechanisms and platforms, it is reasonable to assume that UDFy-38135539 will simply be just another nascent galactic formation on the road to observing the universe of the past and the its formation.
“Spectroscopic confirmation of a galaxy at redshift z=8.6,” Nature.com
“Scientists pinpoint the farthest galaxy,” MSNBC.msn.com
“Farthest Galaxy Found, Perhaps,” Space.com
“Exploding star is oldest object seen in the universe,” CNN.com