One of the first spectacular images taken by NASA’s new multi-million pound James Webb Space Telescope captured the universe’s earliest galaxies.
Now, early analysis has zeroed in on one of these galaxies nine billion light-years away from Earth, and revealed that it is sparkling with some of the oldest-known star clusters, dating back to shortly after the Big Bang.
These dense groups of millions of stars may be relics that contain the first and oldest stars in the universe.
Dubbed ‘the Sparkler galaxy’, it got its name thanks to the compact objects appearing as small yellow-red dots surrounding it, referred to by researchers as ‘sparkles.’
They assumed that the sparkles could either be young clusters of actively-forming stars — born three billion years after the Big Bang at the peak of star formation — or old globular clusters.
Globular clusters are ancient collections of stars from a galaxy’s infancy and contain clues about its earliest phases of formation and growth.
From their initial analysis of 12 of these compact objects, the experts established that five of them are not only globular clusters but among the oldest ones known.
Coming into focus: One of the first spectacular images taken by NASA’s James Webb Space Telescope saw it capture the universe’s earliest galaxies. Now, early analysis has zeroed in on one of these, the ‘Sparkler galaxy’ (pictured) nine billion light-years away from Earth
Their research revealed that the galaxy is sparkling with some of the oldest known star clusters
Experts at the Canadian NIRISS Unbiased Cluster Survey studied the Webb Deep Field image
The research was carried out by experts at the Canadian NIRISS Unbiased Cluster Survey (CANUCS), who studied the James Webb Space Telescope (JWST) Deep Field image.
‘JWST was built to find the first stars and the first galaxies and to help us understand the origins of complexity in the universe, such as the chemical elements and the building blocks of life,’ said Lamiya Mowla, of the University of Toronto and co-lead author of the study.
‘This discovery in Webb’s First Deep Field is already providing a detailed look at the earliest phase of star formation, confirming the incredible power of JWST.’
The Milky Way galaxy has about 150 globular clusters, and how and when exactly these dense clumps of stars formed is not well understood.
Astronomers know that globular clusters can be extremely old, but it is incredibly challenging to measure their ages.
Using very distant globular clusters to age-date the first stars in distant galaxies has not been done before and is only possible with Webb.
‘These newly-identified clusters were formed close to the first time it was even possible to form stars,’ said Mowla.
‘Because the Sparkler galaxy is much farther away than our own Milky Way, it is easier to determine the ages of its globular clusters.
‘We are observing the Sparkler as it was nine billion years ago, when the universe was only four-and-a-half billion years old, looking at something that happened a long time ago.
The Milky Way galaxy has about 150 globular clusters, and how and when exactly these dense clumps of stars formed is not well understood
From their initial analysis of 12 of the compact objects in the Sparkler galaxy, the experts established that five of them are not only globular clusters but among the oldest ones known
Until now, astronomers could not see the surrounding compact objects of the Sparkler galaxy with Hubble
‘Think of it as guessing a person’s age based on their appearance — it’s easy to tell the difference between a 5 and 10-year-old, but hard to tell the difference between a 50 and 55-year-old.’
Kartheik G. Iyer, of the University of Toronto and co-lead author of the study, said: ‘Looking at the first images from JWST and discovering old globular clusters around distant galaxies was an incredible moment, one that wasn’t possible with previous Hubble Space Telescope imaging.
‘Since we could observe the sparkles across a range of wavelengths, we could model them and better understand their physical properties, like how old they are and how many stars they contain.
‘We hope the knowledge that globular clusters can be observed at from such great distances with JWST will spur further science and searches for similar objects.’
Until now, astronomers could not see the surrounding compact objects of the Sparkler galaxy with Hubble.
This changed with Webb’s increased resolution and sensitivity, unveiling the tiny dots surrounding the galaxy for the first time in its first Deep Field image.
The Sparkler galaxy is special because it is magnified by a factor of 100 due to an effect called gravitational lensing — where the SMACS 0723 galaxy cluster in the foreground distorts what is behind it, much like a giant magnifying glass.
Moreover, gravitational lensing produces three separate images of the Sparkler, allowing astronomers to study the galaxy in greater detail.
Dubbed ‘the Sparkler galaxy’, it got its name thanks to the compact objects appearing as small yellow-red dots surrounding it, referred to by CANUCS researchers (pictured) as ‘sparkles’
Webb’s increased resolution and sensitivity unveiled the tiny ‘sparkler’ dots surrounding the galaxy for the first time in its first Deep Field image
‘Our study of the Sparkler highlights the tremendous power in combining the unique capabilities of JWST with the natural magnification afforded by gravitational lensing,’ said CANUCS team lead Chris Willott, from the National Research Council’s Herzberg Astronomy and Astrophysics Research Centre.
‘The team is excited about more discoveries to come when JWST turns its eye on the CANUCS galaxy clusters next month.’
The researchers combined new data from JWST’s Near-Infrared Camera (NIRCam) with HST archival data. NIRCam detects faint objects using longer and redder wavelengths to observe past what is visible to the human eye and even HST.
Both magnifications due to the lensing by the galaxy cluster and the high resolution of JWST are what made observing compact objects possible.
The Canadian-made Near-Infrared Imager and Slitless Spectrograph (NIRISS) instrument on the JWST provided independent confirmation that the objects are old globular clusters because the researchers did not observe oxygen emission lines — emissions with measurable spectra given off by young clusters that are actively forming stars.
NIRISS also helped unravel the geometry of the triply-lensed images of the Sparkler.
‘JWST’s made-in-Canada NIRISS instrument was vital in helping us understand how the three images of the Sparkler and its globular clusters are connected,’ said Marcin Sawicki, a professor at Saint Mary’s University in Canada and study co-author.
‘Seeing several of the Sparkler’s globular clusters imaged three times made it clear that they are orbiting around the Sparkler galaxy rather than being simply in front of it by chance.’
Future studies will also model the galaxy cluster to understand the lensing effect and execute more robust analyses to explain the star formation histories.
The research has been published in The Astrophysical Journal Letters.
The James Webb Telescope: NASA’s $10 billion telescope is designed to detect light from the earliest stars and galaxies
The James Webb telescope has been described as a ‘time machine’ that could help unravel the secrets of our universe.
The telescope will be used to look back to the first galaxies born in the early universe more than 13.5 billion years ago, and observe the sources of stars, exoplanets, and even the moons and planets of our solar system.
The vast telescope, which has already cost more than $7 billion (£5 billion), is considered a successor to the orbiting Hubble Space Telescope
The James Webb Telescope and most of its instruments have an operating temperature of roughly 40 Kelvin – about minus 387 Fahrenheit (minus 233 Celsius).
It is the world’s biggest and most powerful orbital space telescope, capable of peering back 100-200 million years after the Big Bang.
The orbiting infrared observatory is designed to be about 100 times more powerful than its predecessor, the Hubble Space Telescope.
NASA likes to think of James Webb as a successor to Hubble rather than a replacement, as the two will work in tandem for a while.
The Hubble telescope was launched on April 24, 1990, via the space shuttle Discovery from Kennedy Space Centre in Florida.
It circles the Earth at a speed of about 17,000mph (27,300kph) in low Earth orbit at about 340 miles in altitude.
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