An intensive survey deep into the universe by NASA's Hubble and Spitzer space telescopes has yielded the proverbial needle-in-a-haystack: the farthest galaxy yet seen in an image that has been stretched and amplified by a phenomenon called gravitational lensing.
An intensive survey deep into the universe by NASA's Hubble and Spitzer space telescopes has yielded the proverbial needle-in-a-haystack: the farthest galaxy yet seen in an image that has been stretched and amplified by a phenomenon called gravitational lensing.
The embryonic galaxy named SPT0615-JD existed when the universe was just 500 million years old. Though a few other primitive galaxies have been seen at this early epoch, they have essentially all looked like red dots, given their small size and tremendous distances. However, in this case, the gravitational field of a massive foreground galaxy cluster not only amplified the light from the background galaxy but also smeared the image of it into an arc (about 2 arcseconds long).
"No other candidate galaxy has been found at such a great distance that also gives you the spatial information that this arc image does. By analyzing the effects of gravitational lensing on the image of this galaxy, we can determine its actual size and shape," said the study's lead author, Brett Salmon of the Space Telescope Science Institute in Baltimore. He is presenting his research at the 231st meeting of the American Astronomical Society in Washington.
First predicted by Albert Einstein a century ago, the warping of space by the gravity of a massive foreground object can brighten and distort the images of far more distant background objects. Astronomers use this "zoom lens" effect to go hunting for amplified images of distant galaxies that otherwise would not be visible with today's telescopes.
Read more at NASA Jet Propulsion Laboratory, California Institute of Technology
Image: This Hubble Space Telescope image shows the farthest galaxy yet seen in an image that has been stretched and amplified by a phenomenon called gravitational lensing. Credits: NASA, ESA, and B. Salmon (STScI)
