Philippa Kaur

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    in Space & Astronomy

    The James Webb telescope found six galaxies that may be too hefty for their age

    The James Webb Space Telescope’s first peek at the distant universe unveiled galaxies that appear too big to exist.

    Six galaxies that formed in the universe’s first 700 million years seem to be up to 100 times more massive than standard cosmological theories predict, astronomer Ivo Labbé and colleagues report February 22 in Nature. “Adding up the stars in those galaxies, it would exceed the total amount of mass available in the universe at that time,” says Labbé, of the Swinburne University of Technology in Melbourne, Australia. “So you know that something is afoot.”

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    The telescope, also called JWST, released its first view of the early cosmos in July 2022 (SN: 7/11/22). Within days, Labbé and his colleagues had spotted about a dozen objects that looked particularly bright and red, a sign that they could be massive and far away.

    “They stand out immediately, you see them as soon as you look at these images,” says astrophysicist Erica Nelson of the University of Colorado Boulder.

    Measuring the amount of light each object emits in various wavelengths can give astronomers an idea of how far away each galaxy is, and how many stars it must have to emit all that light. Six of the objects that Nelson, Labbé and colleagues identified look like their light comes from no later than about 700 million years after the Big Bang. Those galaxies appear to hold up to 10 billion times the mass of our sun in stars. One of them might contain the mass of 100 billion suns.

    “You shouldn’t have had time to make things that have as many stars as the Milky Way that fast,” Nelson says. Our galaxy contains about 60 billion suns’ worth of stars — and it’s had more than 13 billion years to grow them. “It’s just crazy that these things seem to exist.”

    In the standard theories of cosmology, matter in the universe clumped together slowly, with small structures gradually merging to form larger ones. “If there are all these massive galaxies at early times, that’s just not happening,” Nelson says.

    One possible explanation is that there’s another, unknown way to form galaxies, Labbé says. “It seems like there’s a channel that’s a fast track, and the fast track creates monsters.”

    But it could also be that some of these galaxies host supermassive black holes in their cores, says astronomer Emma Curtis-Lake of the University of Hertfordshire in England, who was not part of the new study. What looks like starlight could instead be light from the gas and dust those black holes are devouring. JWST has already seen a candidate for an active supermassive black hole even earlier in the universe’s history than these galaxies are, she says, so it’s not impossible.

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    Finding a lot of supermassive black holes at such an early era would also be challenging to explain (SN: 3/16/18). But it wouldn’t require rewriting the standard model of cosmology the way extra-massive galaxies would.

    “The formation and growth of black holes at these early times is really not well understood,” she says. “There’s not a tension with cosmology there, just new physics to be understood of how they can form and grow, and we just never had the data before.”

    To know for sure what these distant objects are, Curtis-Lake says, astronomers need to confirm the galaxies’ distances and masses using spectra, more precise measurements of the galaxies’ light across many wavelengths (SN: 12/16/22).

    JWST has taken spectra for a few of these galaxies already, and more should be coming, Labbé says. “With luck, a year from now, we’ll know a lot more.” More

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    in Humans

    Don’t Miss: Learning about how the first black hole image was taken

    New Scientist’s weekly round-up of the best books, films, TV series, games and more that you shouldn’t miss

    Humans

    15 February 2023

    ESO
    Visit
    Echoes from the edge of space and time is a talk by Ziri Younsi, one of the team to take the first picture of a black hole (pictured above) using the Event Horizon Telescope. At the Royal Institution in London at 2pm GMT on 25 February.

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    in Humans

    Hello Tomorrow! review: Selling holiday homes on the moon

    Apple TV+’s compelling new science-fiction offering is a retro-futurist piece, more 20th-century US social drama than technofest

    Humans

    15 February 2023

    By Bethan Ackerley
    Myrtle Mayburn (Alison Pill) has big doubts about her lunar holiday homeApple TV+
    Hello Tomorrow!
    Amit Bhalla, Lucas Jansen
    Apple TV+
    THERE is a certain school of thought that says “real” science fiction must be full of ideas about how science and technology might change our world. This is often called “hard” sci-fi, and there are those who view any deviation from this style with as bellicose an attitude as possible.
    I am not a purist: I prefer to think of sci-fi as a broad church, with the power to imagine almost … More

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    in Humans

    Early risers may have inherited faster body clocks from Neanderthals

    Modern humans who have inherited genetic variants related to circadian rhythms from extinct hominins are more likely to be morning people

    Humans

    15 February 2023

    By Carissa Wong
    Genetics may explain why some of us find mornings easier than othersoatawa/iStockphoto/Getty Images
    Genetic variants that some people have inherited from their Neanderthal and Denisovan ancestors may increase the odds that they are morning rather than evening people.
    “This was really exciting to us, and not expected,” says Tony Capra at the University of California, San Fransisco. “Neanderthals and Denisovans passed on DNA that increased our morningness, and this has been retained in modern human populations.”
    Following a split from our common ancestor with archaic humans such as Neanderthals and Denisovans around … More

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    in Humans

    Couples are most in love in Hungary, according to science

    People in romantic relationships in 45 countries were asked how strongly they agreed with statements such as “just seeing my partner excites me”

    Humans

    14 February 2023

    By Alice Klein
    Research into love may help us understand the emotion and increase understanding between culturesKathrin Ziegler/Digital Vision/Getty Images
    People in relationships report being more in love if they live in a country with high living standards, greater gender equality and a community‑centred culture.
    To find out how experiences of love differ, Piotr Sorokowski at the University of Wrocław, Poland, and his colleagues surveyed 9474 adults in any form of romantic relationship across six continents.
    The participants were given 45 statements, such as “just seeing my partner excites me”, and were asked how strongly … More

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    in Humans

    Curly hair may have evolved to protect early humans from the sun

    In the first study to look at the evolution of hair types, researchers found tightly coiled hair provides a trade-off of shielding the head from the sun while minimising unwanted insulating

    Humans

    14 February 2023

    By Michael Le Page
    Hair type has previously been studied by researchers in fields such as cosmetics and forensics, but not from an evolutionary perspectiveMireya Acierto/Getty Images
    Hair that is tightly coiled offers the best protection against the sun’s potentially damaging rays, which could explain why this trait evolved in early humans in Africa and straighter hair emerged as some humans moved into cooler areas.
    It has long been suggested that the reason our body hair became so fine that it is sometimes barely visible, while our scalp hair remained thick, is to prevent our heads … More

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    in Space & Astronomy

    The James Webb telescope spotted the earliest known ‘quenched’ galaxy

    The James Webb Space Telescope has spotted the earliest known galaxy to abruptly stop forming stars.

    The galaxy, called GS-9209, quenched its star formation more than 12.5 billion years ago, researchers report January 26 at arXiv.org. That’s only a little more than a billion years after the Big Bang. Its existence reveals new details about how galaxies live and die across cosmic time.

    “It’s a remarkable discovery,” says astronomer Mauro Giavalisco of the University of Massachusetts Amherst, who was not involved in the new study. “We really want to know when the conditions are ripe to make quenching a widespread phenomenon in the universe.” This study shows that at least some galaxies quenched when the universe was young.

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    GS-9209 was first noticed in the early 2000s. In the last few years, observations with ground-based telescopes identified it as a possible quenched galaxy, based on the wavelengths of light it emits. But Earth’s atmosphere absorbs the infrared wavelengths that could confirm the galaxy’s distance and that its star-forming days were behind it, so it was impossible to know for sure.

    So astrophysicist Adam Carnall and colleagues turned to the James Webb Space Telescope, or JWST. The observatory is very sensitive to infrared light, and it’s above the blockade of Earth’s atmosphere (SN: 1/24/22). “This is why JWST exists,” says Carnall, of the University of Edinburgh. JWST also has much greater sensitivity than earlier telescopes, letting it see fainter, more distant galaxies. While the largest telescopes on the ground could maybe see GS-9209 in detail after a month of observing, “JWST can pick this stuff up in a few hours.”

    Using JWST observations, Carnall and colleagues found that GS-9209 formed most of its stars during a 200-million-year period, starting about 600 million years after the Big Bang. In that cosmically brief moment, it built about 40 billion solar masses’ worth of stars, about the same as the Milky Way has.

    That quick construction suggests that GS-9209 formed from a massive cloud of gas and dust collapsing and igniting stars all at once, Carnall says. “It’s pretty clear that the vast majority of the stars that are currently there formed in this big burst.”

    Astronomers used to think this mode of galaxy formation, called monolithic collapse, was the way that most galaxies formed. But the idea has fallen out of favor, replaced by the notion that large galaxies form from the slow merging of many smaller ones (SN: 5/17/21).

    “Now it looks like, at least for this object, monolithic collapse is what happened,” Carnall says. “This is probably the clearest proof yet that that kind of galaxy evolution happens.”

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    As to what caused the galaxy’s star-forming frenzy to suddenly stop, the culprit appears to be an actively feeding black hole. The JWST observations detected extra emission of infrared light associated with a rapidly swirling mass of energized hydrogen, which is a sign of an accreting black hole. The black hole appears to be up to a billion times the mass of the sun.

    To reach that mass in less than a billion years after the birth of the universe, the black hole must have been feeding even faster earlier on in its life, Carnall says (SN: 3/16/18). As it gorged, it would have collected a glowing disk of white-hot gas and dust around it.

    “If you have all that radiation spewing out of the black hole, any gas that’s nearby is going to be heated up to an incredible extent, which stops it from falling into stars,” Carnall says.

    More observations with future telescopes, like the planned Extremely Large Telescope in Chile, could help figure out more details about how the galaxy was snuffed out. More

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    in Humans

    Early hominin Paranthropus may have used sophisticated stone tools

    Stone tools discovered in Kenya are the oldest Oldowan-type implements found, dating back at least 2.6 million years, and they may have been made by our relative Paranthropus

    Humans

    9 February 2023

    By Michael Marshall
    Reconstruction of Paranthropus, an early hominin whose teeth were found alongside stone tools at Nyayanga, KenyaELISABETH DAYNES/SCIENCE PHOTO LIBRARY
    A set of stone tools found in Kenya is the oldest of its kind, and one of the oldest known to have been made by ancient hominins. The find adds to the evidence for widespread tool use relatively early in human evolution.
    The artefacts were found with two teeth belonging to hominins called Paranthropus. They weren’t thought to make tools because their teeth were well-suited to chewing food, but the new find suggests they actually did make and use stone tools.
    The finds come from Nyayanga on the north-eastern shore of Lake Victoria in Kenya. Tom Plummer at Queens College, City University of New York first learned of them more than 20 years ago, when he was working at another archaeological dig nearby. There, team member Blasto Onyango at the National Museums of Kenya in Nairobi mentioned a different site with similar tools. “We surveyed,” says Plummer, “we saw some material on the surface”, but it took until 2015 to begin full excavations.Advertisement
    The team has since recovered 330 stone artefacts. They include the heavy cores of pebbles, used for pounding, and sharp cutting flakes that had been removed from them. The tools are a type known as Oldowan, named for Oldupai gorge in Tanzania where the first examples were found.
    Based on analyses of the sediments in which the Nyayanga tools were found, and the types of fossils found with them, the team estimates they are between just over 3 million and 2.6 million years old. “We think it’s in the older end of that range,” says Plummer. This would make them the oldest Oldowan tools on record. Previously, the oldest known examples were those from Ledi-Geraru in Ethiopia, which are from 2.6 million years ago.
    The Nyayanga tools were used to process a variety of foods, says Rahab Kinyanjui, also at the National Museums of Kenya. The team found bones of hippopotamus-like animals, some of which had cut marks on them, suggesting the tools were used for butchery. The heavier implements were also used to pound plant materials like tubers and fruit.
    Early Oldowan stone tools from Nyayanga, KenyaT.W. Plummer, J.S. Oliver, and E. M. Finestone, Homa Peninsula Paleoanthropology Project
    Finding evidence of Oldowan tool use this early in Kenya, and 1300km from Ledi-Geraru in Ethiopia, suggests stone tool use was already widespread, says Plummer. In line with this, stone tools have been found in Algeria from 2.4 million years ago.
    The use of such implements is primarily associated with the Homo genus, which includes our own species Homo sapiens, as well as older ones like Homo erectus. The oldest purported Homo remains are 2.8 million years old, but none have been found at Nyayanga. The only hominin remains there so far are of Paranthropus.
    Paranthropus lived alongside other hominins, including Homo, for over a million years. However, it is generally thought that they have no living descendants. Compared with other hominins from the same time, they looked less like us: in particular, they had very large teeth, perhaps for grinding up tough plant foods.
    “The thing about Paranthropus is they’ve got a really specialised anatomy,” says Plummer. “They’ve got the biggest jaws and teeth of any primate that ever lived, for their weight.” He says it is unlikely that a tool-using animal would need such powerful chewing apparatus. Nevertheless, it is the only hominin found at Nyayanga so far, so he says it is worth seriously considering that Paranthropus made and used the tools.
    Others are less hesitant. “People are very shy about saying that it was not Homo something, Homo habilis or whatever, making tools,” says Margherita Mussi of the Italo-Spanish Archaeological Mission at Melka Kunture and Balchit, based in Rome. She points out that several modern primates sometimes make crude stone tools, including chimpanzees and various monkeys. “So why not a Paranthropus?”

    If that is true, it would fit with other evidence that species of Homo were not the only hominins that made stone tools. The oldest known stone tools of any kind, at 3.3 million years old, are from Lomekwi in Kenya. They are cruder than Oldowan versions and were made in a different way: by hitting rocks on the ground, rather than by hitting a rock held in the hand.
    “We have no genus Homo at that time,” says Sonia Harmand at Stony Brook University in New York, one of the discoverers of the Lomekwi tools. “We already know that the first stone tools were probably not made by Homo.” Australopithecus species are likely candidates.
    For the later Nyayanga tools, there were probably late Australopithecus, early Paranthropus and early Homo in the region. “We have to imagine it’s all these species probably sharing the same territory or the same environment at the same time,” says Harmand.
    Studies like these suggest tool use goes back further than we thought, says Plummer. “We’re going to be pushing tool use further back in time,” he says. Furthermore, “tool use was more important earlier on than we realised”.
    In line with this, Mussi and her colleagues showed last month that some hominins were making obsidian tools in organised “workshops” 1.2 million years ago, 500,000 years earlier than thought. “I think that we are systematically under-evaluating hominins,” says Mussi.

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