Latest news with #LOFAR
Time of India
3 days ago
- Science
- Time of India
Astronomers discover the largest, oldest black hole jet ever
Astronomers have made a record discovery by observing the most massive and oldest black hole jet ever seen, which belongs to the quasar J1601+3102. The over 200,000 light-years-long jet, nearly twice as long as our Milky Way galaxy, is a one-of-a-kind glimpse into the early universe. The light from this quasar began its journey to Earth more than 12 billion years ago, and thus scientists can study the universe as it appeared when it was 1.2 billion years old, about 9% of its present age. The quasar J1601+3102 is powered by a massive black hole with a mass of approximately 450 million times the mass of our Sun. That's significant but modest by comparison to other quasars, whose black holes are billions of times more massive than the Sun. The finding overturns previous theories that only very large black holes were able to produce such gigantic jets, and it indicates that early universe black holes with a range of masses played an important role in the environment around them. All about this jet The observation was made possible through the collaborative power of some advanced telescopes: LOFAR (Low-Frequency Array): A system of European radio telescopes that first detected the jet. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Has Honda Done It Again? The New Honda CR-V is Finally Here. TheFactualist Undo Gemini Near-Infrared Spectrograph (GNIRS):Located in Hawaii, this facility allowed astronomers to measure the redshift of the quasar, how far away it is, and how old it is. Hobby-Eberly Telescope: Based in Texas, this telescope provided optical data to further elucidate the quasar and the jet. Implications for cosmic evolution The vast size of the jet would mean that even relatively small early-universe black holes would have been able to produce such energetic jets. They would have played a significant part in galaxy evolution by regulating the formation of stars and dispersing energy over enormous distances. The asymmetry of the jet would imply that environmental conditions may dictate the direction and power of such outflows. It is crucial to comprehend these dynamics to unravel the tangled interactions that determine galaxy formation. This discovery not only provides a glimpse of the activities of black holes in the primordial universe but also underlines the strength of modern radio astronomy. With the upgrading of technology, astronomers anticipate finding more similar phenomena, strengthening our knowledge of the universe's formative periods.
Yahoo
14-03-2025
- Science
- Yahoo
Astronomers crack the case of a mysterious deep space radio signal that repeats every 2 hours
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have cracked the case of a mysterious repeating radio signal that has been a mystery since it was uncovered last year. The team tracked the signal back to a strange binary system containing a dead star or "white dwarf" and a red dwarf stellar companion. The radio pulse repeats every 2 hours and was first detected a decade ago. It came from the direction of the Big Dipper. This new research indicates that the cause of this repeating radio signal is the magnetic fields of the white dwarf and its red dwarf stellar companion slamming together in this tight binary, designated ILTJ1101. Previously, long-period radio bursts like this one had only been traced back to neutron stars, meaning this work puts an entirely new spin on their origins."There are several highly magnetized neutron stars, or magnetars, that are known to exhibit radio pulses with a period of a few seconds," team member and Northwestern astrophysicist Charles Kilpatrick said in a statement. "Some astrophysicists also have argued that sources might emit pulses at regular time intervals because they are spinning, so we only see the radio emission when the source is rotated toward us. "Now, we know at least some long-period radio transients come from binaries. We hope this motivates radio astronomers to localize new classes of sources that might arise from neutron star or magnetar binaries." The team's research was published in the journal Nature Astronomy on Wednesday (March 12). Team leader Iris de Ruiter from the University of Sydney in Australia first discovered the signal in 2024 when she was searching through archival data collected by the Low Frequency Array (LOFAR). LOFAR is the largest radio telescope operating at the lowest frequencies that can be detected from pulse first appeared in LOFAR data in 2015, and after finding its first instance, de Ruiter found six more pulses from the same source. These flashes of radio waves can last anywhere from several seconds to a few minutes. Despite the difference in duration, the pulses repeat regularly, once every two hours. The pulses have some similarities with a cosmic phenomenon called "fast radio bursts" or FRBs," but are much rarer. "The radio pulses are very similar to FRBs, but they each have different lengths," Kilpatrick said. "The pulses have much lower energies than FRBs and usually last for several seconds, as opposed to FRBs, which last milliseconds. "There's still a major question of whether there's a continuum of objects between long-period radio transients and FRBs, or if they are distinct populations." The team wanted to know what the source of these regular radio pulses is, so they performed follow-up investigations with the Multiple Mirror Telescope (MMT) Observatory in Arizona and the McDonald Observatory in Texas. This revealed the origin of the pulses was two stars located around 1,600 light-years from Earth that are pulsing in unison. The two stars whip around each other once every 125.5 minutes. The researchers then further investigated the system for a full two-hour-long cycle using MMT discovering the true nature of this system. The team's detailed observations allowed them to track the system's movement in detail while gaining information from the red dwarf star by breaking its light down into different wavelengths or spectra. "The spectroscopic lines in these data allowed us to determine that the red dwarf is moving back and forth very rapidly with exactly the same two-hour period as the radio pulses," Kilpatrick said. "That is convincing evidence that the red dwarf is in a binary system." This back-and-forth rocking of this star seems to be the result of a barely visible companion in ILTJ1101 gravitationally tugging on it. The variation of the motion revealed to the team the mass of this very faint companion. This allowed them to determine it is a white dwarf, a stellar remnant that is created when a star with around the mass of the sun reaches the end of its life and its collapses while its outer layers are shrugged off. "In almost every scenario, its mass and the fact that it is too faint to see means it must be a white dwarf," Kilpatrick explained. "This confirms the leading hypothesis for the white dwarf binary origin and is the first direct evidence we have for the progenitor systems of long-period radio transients." Related Stories: — Astronomers discover record haul of 25 new repeating 'fast radio bursts' — Record-breaking radio burst could help us find the universe's missing matter — Shortest 'fast radio bursts' ever discovered last only 1 millionth of a second Astronomers are now planning to study the high-energy ultraviolet emissions of ILTJ1101. This could reveal the temperature of the white dwarf and additional details of red dwarf/white dwarf binaries like this one. "It was especially cool to add new pieces to the puzzle,' team leader de Ruiter said. "We worked with experts from all kinds of astronomical disciplines. "With different techniques and observations, we got a little closer to the solution step by step.'
Yahoo
13-03-2025
- Science
- Yahoo
Black holes spew out powerful jets that span millions of light-years – we're trying to understand their whole life cycle
There is a supermassive black hole at the centre of nearly every big galaxy – including ours, the Milky Way (it's called Sagittarius A*). Supermassive black holes are the densest objects in the universe, with masses reaching billions of times that of the Sun. Sometimes a galaxy's supermassive black hole 'wakes up' due to a sudden influx of gas and dust, most likely supplied from a neighbouring galaxy. It begins eating up lots of nearby gas and dust. This isn't a calm, slow or passive process. As the black hole pulls in material, the material gets superheated on a scale of millions of degrees, far hotter than the surface temperature of our Sun, and is ejected from the galaxy at near-light speeds. This creates powerful jets that look like fountains in the cosmos. The accelerated high-speed plasma matter prompts these 'fountains' to emit radio signals that can only be detected by very powerful radio telescopes. This gives them their name: radio galaxies. While black holes are common, radio galaxies are not. Only between 10% and 20% of all galaxies exhibit this phenomenon. Giant radio galaxies are even less common. They account for only 5% of all radio galaxies and take their name from the fact that they reach enormous distances. Some radio galaxies' jets reach nearly 16 million light-years. (That's almost six times the distance between the Milky Way and the Andromeda galaxy.) The largest jet discovered spans nearly 22 million light-years across. Read more: But how do these structures cover such enormous distances? To find out, I led a study in which we used modern supercomputers to develop models that simulated behaviour of giant cosmic jets within a mock universe, constructed on the basis of fundamental physical laws governing the cosmos. This allowed us to observe how radio jets propagate over hundreds of millions of years – a process impossible to track directly in the real universe. These sophisticated simulations provide deeper insights into the life cycle of radio galaxies, highlighting the differences between their early, compact stages and their later, expansive forms. Understanding the evolution of radio galaxies helps us unravel the broader processes that shape the universe. Cutting-edge technology was key to this study. Sensitive observations from world-class radio telescopes like South Africa's MeerKAT and LOFAR in the Netherlands have recently led to several discoveries of cosmic fountains. Read more: However, modelling their origins has been challenging. Tracking events over millions of years is impossible in real-time. That's where supercomputers come in. These high-performance computing systems are designed to process massive amounts of data. They can perform complex simulations at incredible speeds. In this study, their power was crucial for modelling the evolution of giant radio jets over millions of years. The necessary supercomputing power was provided by South Africa's Inter-University Institute for Data Astronomy, a network comprising the University of Pretoria, the University of Cape Town and the University of the Western Cape. Our universe is governed by fundamental forces like gravity, which can be described through mathematical formulas. These formulas, essentially numbers, are fed into supercomputers to create a simulated 'mock universe' that follows the same physical laws as the real cosmos. This allows scientists to experiment with how jets from supermassive black holes evolve over time. With their immense processing power, supercomputers can simulate millions of years of cosmic jet evolution in just a month. Gravity is the dominant force in the universe, pulling heavier matter and dragging nearby lighter matter. If gravity were the only force at play, the universe might have collapsed by now. Yet we see galaxies, galaxy clusters and even life itself thriving. We suspect that these cosmic fountains play a key role in solving the mystery of how this happens. By releasing thermal and mechanical energy, they heat up the surrounding collapsing gas, counteracting gravity and maintaining a balance that sustains cosmic structures. Our models also shed light on why some radio galaxies' jets bend sharply, forming an 'X' shape in radio waves instead of following a straight trajectory, and revealed the conditions under which giant fountains can continue growing even in dense cosmic environments (that is, in a galaxy cluster). The study also suggests that giant radio galaxies may be statistically more common than previously believed. There are potentially thousands of undiscovered giant cosmic fountains. Thanks to world-class telescopes like MeerKAT and LOFAR – and the power of supercomputers – there's plenty more to explore as we try to understand our universe. The research on which this article is based required extensive collaboration with an international team, including Jacinta Delhaize from the University of Cape Town, Joydeep Bagchi from Christ University, India, and DJ Saikia from the Inter-University Centre for Astronomy and Astrophysics in India. Essential contributions by Kshitij Thorat and Roger Deane from the University of Pretoria also played a crucial role in shaping the study. This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Gourab Giri, University of Pretoria Read more: Mysterious radio pulses from space have been tracked down – and the source is not what astronomers expected Taking a leap of faith into imaginary numbers opens new doors in the real world through complex analysis AI doesn't really 'learn' – and knowing why will help you use it more responsibly Gourab Giri does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Yahoo
12-03-2025
- Science
- Yahoo
Source of Mystery Radio Signal Traced to Clash of Magnetic Titans
From across the Milky Way galaxy, something has been sending out signals. Every two hours or so, a pulse of radio waves ripples through space-time, appearing in data going back years. Now a team of astronomers led by Iris de Ruiter of the University of Sydney has identified the source of this mystery signal – and it's something we've never seen before. Around 1,645 light-years from Earth sits a binary star system, containing a white dwarf and a red dwarf on such a close orbit that each revolution smacks their magnetic fields together, producing a burst of radio waves our telescopes can detect. This source has been named ILT J110160.52+552119.62 (ILT J1101+5521). "There are several highly magnetized neutron stars, or magnetars, that are known to exhibit radio pulses with a period of a few seconds," says astrophysicist Charles Kilpatrick of Northwestern University in the US. "Some astrophysicists also have argued that sources might emit pulses at regular time intervals because they are spinning, so we only see the radio emission when [the] source is rotated toward us. Now, we know at least some long-period radio transients come from binaries. We hope this motivates radio astronomers to localize new classes of sources that might arise from neutron star or magnetar binaries." De Ruiter first discovered the signals in data collected by the LOFAR radio telescope array. Further investigation revealed the earliest detection back in 2015. In some ways, the signal looked like a fast radio burst, a type of powerful blast of radio waves thought to originate from erupting magnetars; but there were some puzzling differences. Some fast radio bursts do repeat, and some even exhibit periodic patterns. But fast radio bursts are incredibly powerful, detected from up to billions of light-years across space-time. Only one source of fast radio bursts has been confidently identified within the Milky Way galaxy. Fast radio bursts are also, as the name implies, fast: their duration is just milliseconds at most. The pulses emitted by ILT J1101+5521 came like clockwork, every 125.5 minutes, at lower energies than typically seen for a fast radio burst, and durations that varied but averaged about a minute. The mechanism behind these signals had to be different from fast radio bursts in crucial ways. Small stars that are far away tend to be faint and hard to see. De Ruiter and her colleagues used the Multiple Mirror Telescope in Arizona and the McDonald Observatory in Texas to home in on the source of the pulses to see if they could identify the object that was creating them. As you have learnt, there was not one source, but two: a cool, dim red dwarf star, and a much, much tinier white dwarf, the collapsed core of a star similar to the Sun that has lived and died, leaving a tiny dense lump of star stuff behind, shining brightly with residual heat. These two tiny objects are so close together that their orbital period is just a hair over two hours. The smoking gun was a full, two-hour observation of the red dwarf as it appeared to whip back and forth on the spot – the telltale sign that it was gravitationally entangled with another object, too small and faint to see. The only known object that would fit is a white dwarf. The two objects are so close together that, with every orbit, their magnetic fields and the plasma therein crash together, producing a burst of radio waves that then propagate through the galaxy. "It was especially cool to add new pieces to the puzzle," de Ruiter says. "We worked with experts from all kinds of astronomical disciplines. With different techniques and observations, we got a little closer to the solution step by step." It's the first time that radio pulses have been traced to a binary object. Although they are not fast radio bursts, the discovery suggests that some sources of mystery radio waves in the Universe – including periodic fast radio bursts – may be the product of a binary interaction. The potential energies emitted by magnetars paired with massive stars, for example, would be much, much higher than the pulses of ILT J1101+5521, which could help explain at least some of the repeating fast radio burst sources scattered across the Universe. The team plans next to study ILT J1101+5521 in more detail to identify and analyze the properties of the red dwarf star and, by extension, the white dwarf with which it shares its strange orbital dance. The research has been published in Nature Astronomy. 128 New Moons Found Orbiting Saturn in Mindblowing Discovery Space Force's Secret Plane Returns After More Than a Year in Orbit Study Traces Our Solar System's Journey Through a Massive Galactic Wave
Yahoo
14-02-2025
- Science
- Yahoo
'We were amazed': Astronomers discover oldest, biggest black hole jet in the known universe — and there may be more
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have discovered a black hole jet that erupted into existence when the universe was less than 1.2 billion years old, or roughly 9% its current age. The jet spans 200,000 light-years — twice the width of the Milky Way — making it the largest black hole jet ever observed from such an early epoch. Decades of observations have revealed that black holes that lurk at the centers of galaxies accrete nearby gas and dust into a swirling disk. As this material falls in, it releases immense amounts of energy due to friction, thus driving the black holes to expel some of the material as powerful jets. Although radio telescopes have found hundreds of such jets — even large ones — none have been spotted in the distant, early universe. "This discovery now shows that these jets do exist and we can detect them," Anniek Gloudemans, a postdoctoral research fellow at the National Science Foundation's NOIRLab who led the discovery, told Live Science. In addition to helping astronomers pin down when the first black hole jets formed in the universe, the discovery helps them understand how jets influenced the early evolution of their host galaxies, she added. The newly discovered jet blasts from both sides of an actively feeding black hole — a quasar named J1601+3102, which has 450 million times the mass of the sun and resides at the heart of a galaxy approximately 10 billion to 13 billion light-years from Earth. The quasar was discovered in 2022 by a network of radio antennae in the Netherlands that are part of the Low Frequency Array (LOFAR). That discovery, also led by Gloudemans, had revealed that this quasar completely outshines its host galaxy — so much so that it stood out as the brightest among nearly two dozen of its counterparts surveyed by LOFAR. Related: Black holes could be driving the expansion of the universe, new study suggests This caught Gloudemans' attention, prompting her and her colleagues to conduct follow-up observations. This time, the researchers used all of LOFAR's 51 antennae across Europe, effectively creating a continent-sized radio telescope that improved the level of detail by 20-fold compared with previous observations. The resulting image of the black hole jet was crucial in confirming its size, according to the new study, which was published Feb. 6 in The Astrophysical Journal Letters. Chiefly, that image revealed a northern lobe of the jet located 29,358 light-years from the quasar, as well as a southern blob that appeared to span a whopping 186,954 light-years. Further scrutiny confirmed that the southern blob indeed belonged to the quasar, leading Gloudemans and her colleagues to interpret it as the counterjet, and thus the largest jet observed in the early universe. "We were amazed, but also skeptical, so we made sure to assemble all the evidence before publishing this work," Gloudemans told Live Science. Although not uncommon in the nearby universe, such large jets have remained undetected in the early universe because the radiation left over from the Big Bang, known as the cosmic microwave background, was more intense during earlier epochs, when the universe was smaller and denser. Interactions between this remnant radiation and black hole jets cause the jets — like the newly discovered one — to weaken at radio wavelengths, making their diminished emissions difficult to detect in telescope observations. "It's only because this object is so extreme that we can observe it from Earth, even though it's really far away," Gloudemans said in a statement. Despite the jet's extreme properties, data from the Gemini Observatory in Hawaii show the black hole responsible for the stream is relatively lightweight compared with other quasars from the early universe, which typically have billions of times the sun's mass. This finding suggests the most powerful jets aren't necessarily created from exceptionally massive black holes, or from black holes that are heavily accreting material close to the theoretical limit, Gloudemans told Live Science. RELATED STORIES —Astronomers catch black holes 'cooking' their own meals in bizarre, endless feeding cycle —Scientists discover black holes spinning unexpectedly fast: 'You're essentially looking at its fossil record' —'Impossible' black holes detected by James Webb telescope may finally have an explanation — if this ultra-rare form of matter exists "We were expecting this newly discovered jet to host an extraordinary black hole, but this wasn't the case," she said. More of these extended jets need to be discovered in the early universe for astronomers to better understand how common they were, she said, "but this work at least suggests that a black hole does not need to have an exceptional mass to generate such a jet at this epoch." The immense energy released by black hole jets can alter the evolution of galaxies through several interconnected mechanisms that regulate the amount of material available for forming stars. Therefore, J1601+3102 will be a valuable cosmic laboratory for studying how jets influence galaxies in the early universe. Future observations are likely to reveal more extended radio jets in the early universe, according to Gloudemans. "There are definitely more of these extended radio jets out there," she said.
