Latest news with #SDSS
Yahoo
5 days ago
- Science
- Yahoo
36 Billion Suns: Record Black Hole Discovery Could Be as Big as They Get
A black hole deep in the cosmos, some 5 billion light-years away, could be the most massive ever found. The galaxy SDSS J1148+1930 harbors a behemoth, around 36.3 billion times the mass of our Sun, according to new measurements. That places the black hole's mass very close to the practical upper limit. For context, the Milky Way's central black hole is a piddling 4.3 million solar masses. This newly discovered black hole no longer fits within the category of supermassive – the giant beast of a thing is ultramassive. Related: Black Holes Could Get So Humongous, Astronomers Came Up With a New Size Category "This is amongst the top 10 most massive black holes ever discovered, and quite possibly the most massive," says astrophysicist Thomas Collett of the University of Portsmouth in the UK. "Most of the other black hole mass measurements are indirect and have quite large uncertainties, so we really don't know for sure which is biggest. However, we've got much more certainty about the mass of this black hole thanks to our new method." Supermassive black holes, larger than about a million solar masses, are thought to lurk in the heart of every full-sized galaxy, the gravitational hub around which everything else in the galaxy revolves. Theoretically, there's no limit to how massive a black hole could grow. In practical terms, other constraints, such as the growth rate, suggest that the maximum mass a black hole could achieve within the current 13.8-billion-year lifespan of the Universe is about 50 billion solar masses. The only way we can test these upper limits, however, is by finding the black holes involved. Which brings us to a fascinating feature in Earth's sky known as the Cosmic Horseshoe. This is a horseshoe-shaped smear of light arcing around a central glowing blob – the result of a rare cosmic alignment called a gravitational lens. Each of the two components – the smear and the blob – are along the same line of sight, at different distances. The blob is actually a galaxy so massive that its gravitational field warps and magnifies the light from a more distant light source. That's what makes the smear. We can learn a lot about distant stars and galaxies magnified this way, but in this case, it's the foreground blob in which a team of astronomers led by Carlos Melo-Carneiro of the Federal University of Rio Grande do Sul in Brazil discovered their astonishing black hole. "This discovery was made for a 'dormant' black hole – one that isn't actively accreting material at the time of observation," Melo-Carneiro says. "Its detection relied purely on its immense gravitational pull and the effect it has on its surroundings." In a lensed system, the extent of the lensing reveals the strength of the gravitational field, which is linked to the mass of the foreground object. Since the masses of supermassive black holes are proportional to the masses of their galaxies, this is one way to calculate the mass of a black hole at a galactic center. Another tool for determining the mass of quiescent black holes involves stellar kinematics – the way stars and other material whirl around. Long-term observations of orbits around the Milky Way's galactic center, for example, confirmed the presence of the black hole therein and provided a measure for its mass. The Cosmic Horseshoe was discovered in 2007. Observations taken at intervals since then allowed the researchers to determine the motions at play in the galactic center. Combined with analysis of the radial arc of the more distant galaxy, the results gave what the researchers say is a very robust measurement. Heavier black holes have been detected, but the measurements are perhaps a little less confident. TON-618 is a famous example. Its mass was initially thought to be around 66 billion solar masses; however, this was revised down in 2019 to about 40 billion solar masses based on galactic kinematics. What makes SDSS J1148+1930 a little more exciting, however, is that it's what is known as a fossil galaxy. This is a single, massive blob of a galaxy that was once a galaxy cluster. The researchers believe that, over time, the galaxies in the cluster – each with a supermassive black hole in its center – merged, their black holes also eventually glomming into one big 36 billion solar mass black hole. It's a huge clue about one of the Universe's many open questions: how supermassive black holes get so enormous. In the Cosmic Horseshoe, "we're seeing the end state of galaxy formation and the end state of black hole formation," Collett says. The discovery has been published in the Monthly Notices of the Royal Astronomical Society. Related News NASA Rovers Keep Getting Stuck, And We Finally Know Why Wild New Theory Suggests Gravitational Waves Shaped The Universe August's Full Sturgeon Moon Is Here: What It Is And How to See It Solve the daily Crossword
Hamilton Spectator
02-05-2025
- Entertainment
- Hamilton Spectator
SDSS Eco Club hopes Earth Week starts 'ripple effect' across the community
Stratford District Secondary School (SDSS)'s Eco Club proves once again that it doesn't take a lot of people to do something extraordinary. 'Usually people think that what they do won't be enough to change the world,' Eco Club member Naz Karazeyeek said. 'But if they got out of that thought and actually started doing stuff one by one, we would make a river, a lake basically, drop by drop. It's more about one person standing up and taking action.' 'When one person does it and they share what they're doing with people, it just keeps growing,' Rowan Watson agreed. 'And then exponentially people will start changing things that they do in their lives and maybe even reaching out to their communities and helping everyone change.' 'The thought that if you start doing something like recycling it's not going to change anything … it will,' Rory Auster said. 'Because of the ripple effect.' Outreach and education were front and centre this week as the club, which has about 20-30 environmentally conscious students this year, hosted Earth Week at SDSS from April 21-25. As Ewan Mann said, the focus of the week was on education. While the climate crisis is one top of mind for many people, chief of all the youth, the members of the club who spoke with the Times said that not every young person is engaged or believes in the crisis. 'The Eco Club is fairly aware, I would say the school at large is fairly unaware,' Mann said. '(Earth) week is the only time where we get to make people a little more aware,' Watson added. A number of guest speakers, like the City of Stratford's climate change manager Sadaf Ghalib and Climate Momentum's Bill James-Abra, came to the school to discuss what they do to tackle the climate crisis locally, among other feature events and speakers. The 'Where's Bruno?' trend was a highlight for Zach Kritzer. The annual event has the school mascot Bruno hiding somewhere in the school and after a photo of him and a question is released over the announcements, students rush to find the bear – the first person to find him and answer the question gets treats to take back to their class. Like every year, the trend was a huge success with a lot of engagement. For Watson, having Claire Scott of Claire Upcycled, a locally based eco-fashion streetwear brand, come and talk with students and show them how to make their own shirts was another peak feature of the week. The week culminated with a trip that Friday to West Five, a sustainable housing development in London that 'represents the future of sustainable living, planned to harmonize modern urban living with environmental stewardship,' according to the development's website. Aside from the week, the Eco Club has been hard at work with its extracurricular outreach. The club continues to operate an urban farm on Smith Street, a project that is aimed to grow food for the school and the many nearby neighbours. Additionally, they are trying to get compost bins that can handle the compostable utensils and plates the school's culinary program uses. Early this year, members of the club delegated at city council during the budget process, successfully convincing council to hire a new community energy liaison to assist Stratford citizens to find savings related to green initiatives, like governmental grants. For all of their continued work, the club was honoured with the Upper Thames River Conservation Authority's inspiration award in February, which recognizes environmental stewardship and activism in the community. Most excitingly, members of the club will be working with TEDx Stratford to host a student-led speaker series on June 10, with the theme of 'shaping the future.' 'We have three speakers and we are going to talk about something that we're passionate about on that theme,' Naz Karazeyeek said about the plans so far. 'Everything from filming, editing – it's all going to be from our students. So it's going to be a student project.' More details on that project are to follow. All of the club members extended 'our biggest thank you' to teacher Christine Ritsma for all her help and guidance throughout the school year.
Yahoo
05-02-2025
- Science
- Yahoo
Scientists discover black holes spinning unexpectedly fast: 'You're essentially looking at its fossil record'
When you buy through links on our articles, Future and its syndication partners may earn a commission. Scientists have discovered that some supermassive black holes rotate much more rapidly than expected. The discovery came as the result of a new form of "black hole archeology" that links black hole spins to the gas and dust they have consumed to grow over 7 billion years of cosmic history. The findings, courtesy of the Sloan Digital Sky Survey (SDSS) suggest a few things. For one, the early universe may have been more orderly than previously suspected. And secondly, the growth of supermassive black holes through the merger chain of progressively larger and larger black holes (triggered as galaxies collide and merge) may be supplemented by the objects voraciously feasting on surrounding gas and dust. "We have studied the giant black holes found at the centers of galaxies, from today to as far back as seven billion years ago," team member Logan Fries, from the University of Connecticut, said in a statement. "Unexpectedly, we found that they were spinning too fast to have been formed by galaxy mergers alone. "They must have formed in large part from material falling in, growing the black hole smoothly and speeding up its rotation." Despite being cosmic monsters that shape the entire galaxies around them, supermassive black holes with masses millions or billions of times that of the sun (and their more diminutive stellar-mass counterparts) are overall quite can be individually defined by just three characteristics: mass, spin, and, less importantly, electric charge. As physicist John Wheeler wittily explained this lack of distinguishing features: "black holes have no hair." "Black holes seem so exotic, but you can describe them completely with just two numbers: mass and spin rate," Fries explained. "The problem is that mass is hard to measure, and spin is even harder." The speed at which a black hole spins is difficult to distinguish from the speed at which the surrounding flattened cloud of gas and dust — the accretion disk — rotates. "The challenge lies in separating the spin of the black hole from the spin of the accretion disk surrounding it," Jonathan Trump, team member and a University of Connecticut researcher, said in the statement. "The key is to look at the innermost region, where gas is falling into the black hole's event horizon. "A spinning black hole drags that innermost material along for the ride, which leads to an observable difference when we look at the details in our measurements." The team tackled the challenging task of determining the spin of black holes using the SDSS's Reverberation Mapping project. This project has been making extremely precise mass measurements for hundreds of black holes while also conducting detailed observations of the structures of the voids' accretion disks. This data comes in the form of spectra, or light emitted across the electromagnetic spectrum. With this in hand, scientists can begin to measure the rate at which a central black hole spins. A subtle shift in the wavelength of light reveals a great deal about the rotation of the black hole. When material falls into the black hole, it also brings with it angular momentum — that rotation reveals details of a black hole's past diet. 'I call this approach 'black hole archaeology' because we're trying to understand how the mass of a black hole has grown over time,' Fries said. "By looking at the spin of the black hole, you're essentially looking at its fossil record." This "fossil record" can be decoded when scientists compare the observed rate of spin to what is predicted. Currently, the favored model suggests supermassive black holes grow by mergers triggered when their home galaxies collide and merge. Because these individual galaxies have their own rates of rotation and random orientation, when they merge, these rotations could cancel out. Or, at least, they could combine together. Both outcomes should be equally as likely. Given this, scientists expect that black holes should spin very slowly. That isn't what this team discovered, however. Not only did this research reveal that many black holes are spinning more rapidly than expected, but it also showed that black holes in more distant galaxies spin even more quickly than those in the local universe. This suggests the spin of black holes could build gradually over time. One way that could happen is through the black hole's accumulation of angular momentum by its gradual accretion of dust and gas. Related Stories: — NASA X-ray telescope Chandra discovers black holes 'blow' on their food to cool it down — Supermassive black holes in 'little red dot' galaxies are 1,000 times larger than they should be, and astronomers don't know why — Black holes can squash star formation, James Webb Space Telescope finds Researchers could further test this idea and verify these results using observations from the James Webb Space Telescope (JWST), which, in its three years of operation, has been finding supermassive black holes from earlier and earlier epochs of the universe. "Black holes really do sit at the frontier of human understanding," Juna Kollmeier, the Director of SDSS-V, the current phase of the SDSS, said in the statement. "We undertake massive surveys like SDSS to build an empirical astrophysical picture of their fundamental properties against which our theoretical models can be put to the test." Fries presented the team's findings on Jan. 14 at the 245th meeting of the American Astronomical Society (AAS) in National Harbor, Maryland.
