Astronomers detect most distant fast radio burst to date | ESO
From observation of the 'red shift' we know the Universe is expanding and, by calculating the rate of expansion, we can calculate how far away an object is from any point in the Universe such as Earth.
If the creationist superstition were correct, assuming the Universe is expanding at the velocity of light (in fact, it is nowhere near that fast), the farthest objects could be no more than 10,000 light years away. This is the time it would take for light leaving the object to reach Earth, travelling at the velocity of light (186,000 miles per second).
However, an international team of astrophysicists has discovered a remote source of 'fast radio bursts' (FBR) of radio waves lasting less than a millisecond, in a galaxy so far away that its light took eight billion years to reach us! Although this is the farthest FBR source so far discovered, being about 50% farther away than the previous farthest, it is by no means the farthest object so far detected. These are about twice that distance, consistent with the Universe being 14 billion years old. In other words, the Universe has been expanding for much longer than 8 billion years, and for many times longer than the 10,000 years creationists belie.
So, any creationist capable of doing the simple maths should be able to work out that the Universe is far too large and has been expanding far too long for it to have been created 10,000 years ago, by several orders of magnitude.
The location of the FRB source was pinpointed by researchers at the European Southern Observatory (ESO) and its discovery is explained in an ESO press release:
An international team has spotted a remote blast of cosmic radio waves lasting less than a millisecond. This 'fast radio burst' (FRB) is the most distant ever detected. Its source was pinned down by the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in a galaxy so far away that its light took eight billion years to reach us. The FRB is also one of the most energetic ever observed; in a tiny fraction of a second it released the equivalent of our Sun’s total emission over 30 years.Incidentally, this work helps to resolve the problem of the 'missing' matter, i.e., the fact that there appears to be only about half the number of atoms in the Universe compared to what the theory says there should be. One explanation is that this 'missing' matter is so diffusely spread in the space between galaxies that it is difficult to detect. FBRs are scattered by this diffuse dust so can be used to calculate the density of matter in the space between their source and the detector.
The discovery of the burst, named FRB 20220610A, was made in June last year by the ASKAP radio telescope in Australia [1] and it smashed the team’s previous distance record by 50 percent.
“Using ASKAP’s array of dishes, we were able to determine precisely where the burst came from,” says Stuart Ryder, an astronomer from Macquarie University in Australia and the co-lead author of the study published today in Science. “Then we used [ESO’s VLT] in Chile to search for the source galaxy, [2] finding it to be older and further away than any other FRB source found to date and likely within a small group of merging galaxies.”
The discovery confirms that FRBs can be used to measure the 'missing' matter between galaxies, providing a new way to 'weigh' the Universe.
Current methods of estimating the mass of the Universe are giving conflicting answers and challenging the standard model of cosmology. “If we count up the amount of normal matter in the Universe — the atoms that we are all made of — we find that more than half of what should be there today is missing,” says Ryan Shannon, a professor at the Swinburne University of Technology in Australia, who also co-led the study. “We think that the missing matter is hiding in the space between galaxies, but it may just be so hot and diffuse that it's impossible to see using normal techniques.”
“Fast radio bursts sense this ionised material. Even in space that is nearly perfectly empty they can 'see' all the electrons, and that allows us to measure how much stuff is between the galaxies,” Shannon says.
Finding distant FRBs is key to accurately measuring the Universe’s missing matter, as shown by the late Australian astronomer Jean-Pierre ('J-P') Macquart in 2020. “J-P showed that the further away a fast radio burst is, the more diffuse gas it reveals between the galaxies. This is now known as the Macquart relation. Some recent fast radio bursts appeared to break this relationship. Our measurements confirm the Macquart relation holds out to beyond half the known Universe,” says Ryder.
“While we still don’t know what causes these massive bursts of energy, the paper confirms that fast radio bursts are common events in the cosmos and that we will be able to use them to detect matter between galaxies, and better understand the structure of the Universe,” says Shannon.
The result represents the limit of what is achievable with telescopes today, although astronomers will soon have the tools to detect even older and more distant bursts, pin down their source galaxies and measure the Universe’s missing matter. The international Square Kilometre Array Observatory is currently building two radio telescopes in South Africa and Australia that will be capable of finding thousands of FRBs, including very distant ones that cannot be detected with current facilities. ESO’s Extremely Large Telescope, a 39-metre telescope under construction in the Chilean Atacama Desert, will be one of the few telescopes able to study the source galaxies of bursts even further away than FRB 20220610A.
This research was presented in a paper titled “A luminous fast radio burst that probes the Universe at redshift 1” (doi: 10.1126/science.adf2678) to appear in Science.
This discovery is the subject of an article in The Conversation by one of the paper's authors, Ryan Shannon, Associate Professor, Swinburne University of Technology, Melbourne, Australia. His article is reproduced here under a Creative Commons licence, reformatted for stylistic consistency:
We traced a powerful radio signal to the most distant source yet – a galaxy billions of lightyears away
The Australian Square Kilometre Array Pathfinder (ASKAP), the radio telescope used to discover and localise FRB 20220610A. CSIRO
Ryan Shannon, Swinburne University of Technology
Every day and night, hundreds of thousands of intense, brief flashes of radiation suddenly flicker on and then off all across the sky. These “fast radio bursts” are invisible to the naked eye, but to a radio telescope many almost outshine everything else in the sky for a few thousandths of a second.
Since the first such burst was spotted in 2006, we have found that nearly all of them come from distant galaxies. Most bursts pass unnoticed, occurring outside the field of view of radio telescopes, and never occur again.
In new research published in Science, we have found the most distant fast radio burst ever detected: an 8-billion-year-old pulse that has been travelling for more than half the lifetime of the universe.
Seizing the opportunity
Astronomers are fascinated by fast radio bursts for two reasons.
The first is that their cause is unknown. The bursts are a trillion times more energetic than the things that look most like them: rotating neutron stars called pulsars, in our own galaxy.
The second reason is that the bursts provide a new tool to study other aspects of the cosmos.
Fast radio bursts let us study the “cosmic web” of matter floating in the space between galaxies. This matter is very hot, diffuse gas and almost invisible, but it subtly slows down fast radio bursts as they pass through it. (This is ordinary matter, the same kind that makes up stars, planets and humans, not the invisible “dark matter” that also lurks throughout the universe.)
The degree to which bursts slow down correlates with the distance they have travelled.
In 2020, analysis of fast radio bursts revealed that the cosmic web actually contains more than half of the normal matter in the universe – which astronomers had previously thought was “missing”.
In search of the extreme
More distant and extreme fast radio bursts promise to reveal further secrets about the universe, so astronomers are on the hunt. I lead a team doing just that, using the Australian SKA Pathfinder (ASKAP) radio telescope.
On June 6 2022, our team detected and pinpointed a very bright burst with a high degree of slowing (known officially as “FRB 20220610A”). Our initial calculations suggested it might be the most distant ever found.
However, there was a possibility that the burst was closer than we thought – or that it might come from a distant galaxy too faint to be seen with an optical telescope.
We turned to one of the world’s most powerful optical observatories to search for the host galaxy: the Very Large Telescope (VLT) in Chile. The observatory’s four telescopes are equipped with cutting-edge cameras and spectrographs that can identify faint host galaxies and study their properties in detail.
At the position pinpointed by ASKAP as the source of the burst, initial images revealed faint smudges of light that looked like a distant galaxy. Analysing the spectrum of light from the galaxy showed it was strongly “redshifted”, meaning the emission from the burst has doubled in wavelength as it stretched out on its journey through the expanding universe.
The redshift had a value just over 1, which shows the burst was emitted more than 8 billion years ago, when the universe was less than half its present age. This confirmed that FRB 20220610A had broken the record for the most distant fast radio burst.
Pushing the limits of the universe
Like Olympic athletes, astronomers (including me) enjoy breaking records. Beyond personal satisfaction, however, this detection can also be used to explore the two fundamental questions about fast radio bursts.
First, the burst has the most energy of any that has been securely pinpointed to a location. It is more energy than our Sun puts out in 30 years, and approaches what we believe are fundamental physical limits.
The upper limit on the amount of energy any one fast radio burst can carry may be determined by quantum mechanical effects. At a certain point, the burst’s surge of radio photons may meet resistance from a sea of “virtual” electrons and positrons which British physicist Paul Dirac predicted in 1930.
Our discovery also demonstrates the potential for fast radio bursts to study the composition of the distant universe. As we look back in time, we see the structure of galaxies changes a great deal. Bursts in distant galaxies may allow us to study the detailed structure of their hosts.
Delving deeper in the cosmos
We now know that energetic bursts exist in the distant universe. As new and upgraded telescopes join the hunt for fast radio bursts, we are likely to see many more tracked down to their host galaxies.
We are currently building a new fast radio burst search system for ASKAP which will make it five times more sensitive, enabling us to push the frontier of our research further out into the universe.
And in the future, ultra-sensitive radio telescopes such as the Square Kilometre Array (SKA) will be able to detect bursts at ever greater distances. These detections will be used to map the structure of the universe and resolve the tale of a modern astronomical mystery.
Ryan Shannon, Associate Professor, Swinburne University of Technology, Swinburne University of Technology
This article is republished from The Conversation under a Creative Commons license. Read the original article.
No comments:
Post a Comment
Obscene, threatening or obnoxious messages, preaching, abuse and spam will be removed, as will anything by known Internet trolls and stalkers, by known sock-puppet accounts and anything not connected with the post,
A claim made without evidence can be dismissed without evidence. Remember: your opinion is not an established fact unless corroborated.