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Home / Science / Stars were born only 250 million years after the Big Bang, one step closer to the cosmic dawn

Stars were born only 250 million years after the Big Bang, one step closer to the cosmic dawn



Stars in a galaxy 13.28 billion light-years away emerged only 250 million years after the Big Bang.

In a distant galaxy – a galaxy called MACS1149-JD1 – stars were created earlier in the history of the universe, when scientists can directly detect new observations. In addition, the same research revealed that MACS1149-JD1 is the farthest known source of oxygen and the most distant galaxy with accurate range finding, said co-author Nicolas Laporte, a researcher at University College London (UCL), told Space.com

MACS1149-JD1 was first discovered in 2012 as one of the most remote objects on Earth, whose light scientists can observe. Now, the research team led by groups at UCL and Osaka Sangyo University in Japan has made an accurate measure of the galaxy's redshift ̵

1; as the wavelength of the light is stretched, the light shifts to the red end of the spectrum , A redshift measurement can tell us how far the object emits light (in this case, the galaxy), and how fast the universe expands when the light is emitted. [From the Big Bang to Now in 10 Easy Steps]
  The first zoom shows an observation of the galaxy MACS1149-JD1 from the Very Large Telescope of the European Southern Observatory; The second zoom shows a galaxy's Hubble image with contours showing ionized oxygen detected by ALMA.

The first zoom shows an observation of the galaxy MACS1149-JD1 from the Very Large Telescope of the European Southern Observatory; The second zoom shows a galaxy's Hubble image with contours showing ionized oxygen detected by ALMA.

Picture credits: ALMA (ESO / NAOJ / NRAO), NASA / ESA Hubble Space Telescope, Hashimoto et al.

The identification of oxygen revealed the age of the stars in this galaxy. Oxygen is generated in stars and released into the gas clouds in the galaxy when these stars die . The confirmation of the presence of oxygen in MACS1149-JD1 showed how an older generation of stars already existed and died within the system. Although the researchers were not shocked to find oxygen, they were surprised at how early in the history of the universe this oxygen had formed, so they had to further investigate and calculate the age of the stars, Laporte said. [How the Huge ALMA Radio Telescope Works (Infographic)]

Using the Atacama Large Millimeter / Submillimeter Array (ALMA) in Chile, the team measured the properties of a double ionized oxygen emission line in the MACS1149-JD1 spectrum, which showed that the galaxy's redshift was approximately 9 , 11 lies. Larger redshift measurements correspond to weaker, more distant galaxies, and so these measurements led to the conclusion that the galaxy was approximately 550 million years old, according to an UCL statement on the new work.

Through the study of infrared data From the Hubble Space Telescope of NASA / ESA and the NASA Spitzer Space Telescope, the research team observed the brightness of the galaxy. This observation suggests that there was significant star formation in this galaxy only 250 million years after the Big Bang. The ALMA redshift measurement allowed the team to exclude other explanations for this observation, such as the possibility that the observed brightness resulted from strong recombination lines or features associated with the hot-beam radiation, confirming the team's conclusion. 19659002] The team confirmed the galaxy's distance from these observations by ALMA and the Very Large Telescope (VLT) of the European Southern Observatory (ESO).

In future studies, researchers could use even more sensitive measurements to identify the first stars and galaxies in the universe, Laporte said.

"If you want to go back, [you could] you are shifting the observation of galaxies and stars to a very high redshift, 20, 50," he said. By discovering the point in the history of the universe that first formed stars and galaxies – an epoch known as cosmic dawn – scientists would answer one of the greatest secrets of modern astronomy. Did the first galaxies emerge from a completely dark universe? How were these first stars and galaxies? This research could be a step forward in answering these monumental issues, Laporte said.

This new observation, while a groundbreaking measurement of a distant system, is "just a data point in a galaxy," Rychard Bouwens, a researcher not involved in the study and discussing this recent work in a News & Views article in Nature, said Space.com. But while MACS1149-JD1 was only a "glimpse," as Bouwens said, toward cosmic twilight, Bouwens also discussed how the Eagle-Eyed James Webb Space Telescope will take this work even further. "With the planned James Webb Space Telescope," he said, "we will be able to observe many of these systems and make the observations more direct."

So, as this new work takes us far back into the world The advancing telescope technology of the Universe, like the much-anticipated launch of the Webb telescope in the next few years, will, as Bouwens argued, be even closer to the cosmic twilight ,

This work is described in detail today in the Journal (May 16) Nature

E-mail: Chelsea Gohd at cgohd@space.com or follow her @chelsea_gohd . Follow us @SpaceTotcom Facebook and Google+ . Original article on Space.com .


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