NASA announced on Thursday, March 3, 2016 that an international team of astronomers, using the organization’s Hubble Space Telescope, discovered one of the farthest galaxies to date, and named it GN-z11.
Based on images from the Hubble and Spitzer telescopes, the galaxy is located in the direction of the Ursa Major constellation, and seems to have appeared 13.4 billion years ago, or 400 million years after the Big Bang happened.
Astronomers believe that it is 25 times smaller than the Milky Way, and the number of stars that it contains is only one percent of our own galaxy’s star mass.
The team consists of scientists from Yale University, the Space Telescope Science Institute (STSI), and the University of California. These astronomers have been looking into the first galaxies that were formed in the universe, specifically the farthest ones in the galaxy. By discovering this unusually bright galaxy, scientists at NASA have broken the record for cosmic distance.
Main investigator Pascal Oesch of Yale University said, “We’ve taken a major step back in time, beyond what we’d ever expected to be able to do with Hubble. We see GN-z11 at a time when the universe was only three percent of its current age.”
The discovery of this galaxy makes it very possible that other bright galaxies found by the Hubble Telescope are also located at similarly far distances.
In order to find a galaxy like GN-z11, scientists use the Wide Field Camera 3 of the telescope to measure the distance to the galaxy spectroscopically by using a spectroscope – an optical instrument for forming and examining spectra – to determine the composition of the substance from the position of the spectral lines. The specialized camera divides the light into its component colors.
This is what scientists call measuring a galaxy’s “redshift,” which is caused as the universe grows. All objects in the universe seem to be moving away from us because their light is stretched to longer, redder wavelengths as they travel through space, which is slowly expanding.
When the redshifted light from distant galaxies like GN-z11 moves close enough for the telescope to capture, the information taken from the light allows scientists to view the galaxies as they were billions of years ago.
Freshman Saisreeja Jekireddy said, “I think that it’s very interesting how the NASA scientists use redshifted light to find distant galaxies. The new technology that is being used will be very beneficial. At this rate, scientists will probably make many more discoveries and use this evidence to come up with new theories about the universe and its mysteries.”
Prior to the discovery, the most distant galaxy on record was one with a redshift of 8.6, which is equivalent to 13.2 billion years in the past. Recently, the Hubble discovery team has verified that the redshift of GN-z11 is a shocking 11.1, which is about 200 million years closer to the Big Bang.
These new discoveries are just a preview of what can and will be discovered with NASA’s upcoming James Webb Telescope, which will be launched into space in the future around 2018.
Astronomers are surprised, however, because many of the observations made using the Spitzer and Hubble Telescopes were thought only to be attainable through the use of the James Webb Space Telescope.
Freshman Ria Patel said, “It’s fascinating to know that even without NASA’s James Webb Telescope, new complex findings can still be made. It’s true that advancements in technology are useful, but it’s also true that we don’t have to constantly build and build new technology to get new results.”
The discovery of this new galaxy will also have a significant and positive impact on NASA’s planned Wide-Field Infrared Survey Telescope (WFIRST), which currently has the planned ability to locate thousands of similar bright, faraway galaxies.
The team’s observations have been accepted for publication in an impending volume of the “Astrophysical Journal.”
How important do you think discoveries like these are in terms of learning more about our universe and space in general?