A tiny speck of red captured in the far background of the James Webb Space Telescope’s first ‘deep field’ image could change our understanding of the early Universe, astronomers say.
The inconspicuous speck is an ancient, unnamed galaxy that’s 13.1 billion years old — just a few hundred million years younger than the birth of the universe. Of all the galaxies captured in the image, it is the farthest from Earth.
It was captured in the deepest and sharpest infrared image of the distant universe ever recorded and released to the world as part of the $10 billion (£7.4 million) observatory first set of full color pictures last week.
When researchers expand the light from a single galaxy into a spectrum, they can learn about the chemical composition, temperature and density of the galaxy’s ionized gas.
For example, the spectrum of this galaxy will reveal the properties of its gas, which will shed light on how its stars are forming and how much dust it contains.
Never before has such information been captured in this quality from this distance.
Hidden mysteries: A tiny red speck in the far background of the James Webb Space Telescope’s first ‘Deep Field’ image could help unravel the chemistry of the early Universe
When researchers stretch the light from a single galaxy into a spectrum (pictured), they can learn about the chemical composition, temperature and density of a galaxy’s ionized gas
Far away: It was captured in the deepest and sharpest infrared image of the distant Universe ever recorded (pictured) and released last week as part of Webb’s first images
The spectrum itself was generated by Webb’s NIRSpec instrument, which uses tiny windows to isolate and analyze light from objects in the telescope’s field of view.
It meant that only the old galaxy’s starlight was allowed through to reveal its chemical signatures, while other light from nearer bright objects was blocked.
Among the various elements within the galaxy was a fingerprint of glowing oxygen gas known as the emission line.
Oxford University NIRSpec team member Andrew Bunker said experts had hoped to see this line in distant galaxies but expected to have to search through “dozens or hundreds” or targets before spotting it.
“I don’t think we really dreamed it would be there within the first essentially public snap. It’s really quite incredible,” he told the New scientist.
The reason the oxygen emission line is important is because astronomers use it to calibrate their measurements of oxygen compositions of galaxies.
If it can then be compared to other emission lines in a galaxy’s light, it is possible to use the chemical fingerprints in a spectrum to decipher how many chemicals are present in the galaxy.
This has previously been done for nearby galaxies, but not distant ones like the red spot in Webb’s deep field.
When astronomers start analyzing Webb’s data, we’ll learn an incredible amount about galaxies that have existed throughout the cosmos—and how they compare to the beautiful spiral and elliptical galaxies in the nearby Universe.
More spectra like this will allow scientists to study how the proportion of elements heavier than helium has changed over time in distant galaxies.
“It gives you data points on this development,” Emma Chapman, an astrophysicist at the University of Nottingham, told New Scientist.
The spectrum itself was generated by Webb’s NIRSpec instrument, which uses tiny windows to isolate and analyze light from objects in the telescope’s field of view
Webb’s infrared abilities make it possible to see back in time to the Big Bang, which took place 13.8 billion years ago. Light waves travel extremely fast, about 186,000 miles (300,000 km) per second, every second. The further away an object is, the further back in time we look. This is due to the time it takes for the light to travel from the object to us
“So you can think about how quickly the first stars died and polluted the gas [to] create the second generation of stars that make up this galaxy.’
Last week, Webb’s dazzling, unprecedented images of a “stellar nursery,” a dying, dust-shrouded star, and a “cosmic dance” among a cluster of galaxies were shown to the world for the first time.
It put an end to months of waiting and feverish anticipation as people around the world were treated to the first batch of a treasure trove of images that will culminate in the universe’s earliest glimpse of dawn.
Thanks to Webb’s infrared capabilities, it can look back in time to just 100 to 200 million years after the Big Bang and take pictures of the very first stars that shone in the universe more than 13.5 billion years ago.
His first images of nebulae, an exoplanet, and galaxy clusters sparked great celebrations in the scientific world on a “great day for mankind.”
Researchers will soon begin to learn more about the mass, age, history and composition of galaxies as Webb attempts to study the earliest galaxies in the universe.
THE JAMES WEBB TELESCOPE
The James Webb Telescope has been described as a “time machine” that could help unlock the mysteries 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 to observe the sources of stars, exoplanets and even the moons and planets of our solar system.
The giant telescope, which has already cost more than $7 billion (£5 billion), is believed to be the successor to the Hubble orbiting space telescope
The James Webb Telescope and most of its instruments have an operating temperature of about 40 Kelvin – about minus 387 Fahrenheit (minus 233 degrees Celsius).
It is the largest and most powerful orbital space telescope in the world, able to look back 100 to 200 million years after the Big Bang.
The orbiting infrared observatory is said to be about 100 times more powerful than its predecessor, the Hubble Space Telescope.
NASA considers James Webb to be Hubble’s successor rather than a replacement as the two will be working together for a while.
The Hubble Telescope was launched on April 24, 1990 aboard the Space Shuttle Discovery from Kennedy Space Center in Florida.
It orbits the Earth at a speed of about 17,000 mph (27,300 km/h) in low Earth orbit at about 340 miles altitude.
