United States: Scientists have put together a deep-sky mosaic, providing a portrait of the distant universe containing 265,000 galaxies that stretch back through 13.3 billion years of time, using data from NASA’s Hubble Space Telescope.
The image is the largest and most comprehensive “history book” of galaxies dating back to just 500 million years after the Big Bang, researchers said.
Created from nearly 7,500 individual exposures, the image stitches together 16 years worth of observations from the Hubble Space Telescope.
The portrait shows how galaxies change over time, building themselves up to become the giant galaxies seen in the nearby universe.
The ambitious endeavor, called the Hubble Legacy Field, also combines observations taken by several Hubble deep-field surveys, including the extreme Deep Field (XDF), the deepest view of the universe.
The wavelength range stretches from ultraviolet to near-infrared light, capturing the key features of galaxy assembly over time.
“Now that we have gone wider than in previous surveys, we are harvesting many more distant galaxies in the largest such dataset ever produced by Hubble,” said Garth Illingworth of the University of California, Santa Cruz in the US, leader of the team that assembled the image.
“This one image contains the full history of the growth of galaxies in the universe, from their time as ‘infants’ to when they grew into fully fledged ‘adults’,” Illingworth said.
No image will surpass this one until future space telescopes are launched, researchers said.
“We’ve put together this mosaic as a tool to be used by us and by other astronomers,” Illingworth added.
“The expectation is that this survey will lead to an even more coherent, in-depth and greater understanding of the universe’s evolution in the coming years,” he said.
This new image mosaic is the first in a series of Hubble Legacy Field images. The team is working on a second set of images, totaling more than 5,200 Hubble exposures, in another area of the sky.