Latest news with #ChandraXrayObservatory
Yahoo
28-07-2025
- Science
- Yahoo
Rogue black hole found terrorizing unfortunate star in distant galaxy
When you buy through links on our articles, Future and its syndication partners may earn a commission. A rogue, middle-mass black hole has been spotted disrupting an orbiting star in the halo of a distant galaxy, and it's all thanks to the observing powers of the Hubble Space Telescope and Chandra X-ray Observatory. However, exactly what the black hole is doing to the star remains in question as there are conflicting X-ray measurements. Black holes come in different size classes. At the smaller end of the scale are the stellar-mass black holes born in the ashes of supernova explosions. At the top end of the scale are the supermassive black holes, which can grow to have many millions or billions of times the mass of our sun, lurking in the hearts of galaxies. In between those categories are intermediate-mass black holes (IMBH), which have mass ranging from hundreds up to 100,000 solar masses, or thereabouts. "They represent a crucial missing link in black hole evolution between stellar mass and supermassive black holes," Yi-Chi Chang of the National Tsing Hua University in Hsinchu, Taiwan said in a statement. The problem is that intermediate-mass black holes are hard to find, partly because they tend not to be as active as supermassive black holes or as obvious as a stellar-mass black hole when its progenitor star goes supernova. However, occasionally, an IMBH will spark to life when it instigates a tidal disruption event. This happens when a star or gas cloud gets too close to the black hole and gravitational tidal forces rip the star or gas cloud apart, producing bursts of X-rays. "X-ray sources with such extreme luminosity are rare outside galaxy nuclei and can serve as a key probe for identifying elusive IMBHs," said Chang. In 2009, Chandra spotted anomalous X-rays originating from a region 40,000 light-years from the center of a giant elliptical galaxy called NGC 6099, which lies 453 million light-years from us. This bright new X-ray source was called HLX-1, and its X-ray spectrum indicated that the source of the X-rays was 5.4 million degrees Fahrenheit (3 million degrees Celsius), a temperature consistent with the violence of a tidal disruption event. But what followed was unusual. The X-ray emissions reached a peak brightness in 2012 when observed by the European Space Agency's XMM-Newton X-ray space telescope. When XMM-Newton took another look in 2023, it found the X-ray luminosity had substantially dwindled. In the meantime, the Canada–France Hawaii Telescope had identified an optical counterpart for the X-ray emission, one that was subsequently confirmed by Hubble. There are two possible explanations for what happened. The first is that Hubble's spectrum of the object shows a tight, small cluster of stars swarming around the black hole. The black hole might have once been at the core of a dwarf galaxy that was whittled down — unwrapped like a Christmas present — by the gravitational tides of the larger NGC 6099. This process would have stolen away all the dwarf galaxy's stars to leave behind a free-floating black hole with just a small, tight grouping of stars left to keep it company. But the upshot of this is that the cluster of stars is like a stellar pantry to which the black hole occasionally goes to feast. It seems certain that a tidal disruption event involving one of these stars is what Chandra and Hubble have witnessed, but was the star completely destroyed? One possibility is that the star is on a highly elliptical orbit, and at its perihelion (closest point to the black hole) some of the star's mass is ripped away — but the star managed to survive for another day. This would potentially explain the X-ray light curve: The emission from 2009 was as the star was nearing perihelion, while the peak in 2012 was during perihelion, and the latest measurements in 2023 would be when the star was farthest from the black hole and not feeling its effects so much. We might then expect another outburst of X-rays during its next perihelion, whenever that might be. However, there's an alternative hypothesis: The star may have been stripped apart a piece at a time, forming a stream of material around the black hole. When Chandra first detected the X-ray emission from the tidal disruption event, this stream was just beginning to wrap back on itself, the self-intersection giving rise to shock-heating that produced X-rays. Then, the 2012 measurements would have been of a fully-fledged hot accretion disk of gas, the star by now completely ripped apart. The material within this disk would have spiraled into the black hole's maw, thus depleting the disk, which would explain why it is much less luminous in X-rays in 2023. Picking out the correct scenario apart will require further surveillance. "If the IMBH is eating a star, how long does it take to swallow the star's gas? In 2009, HLX-1 was fairly bright. Then, in 2012, it was about 100 times brighter, and then it went down again," Roberto Soria of the Italian National Institute for Astrophysics (INAF), who is a co-author of a new study describing the observations of HLX-1, said in the statement. "So now we need to wait and see if it's flaring multiple times, or if there was a beginning, a peak, and now it's just going to go down all the way until it disappears." Making new observations of an IMBH such as HLX-1 is key to better understanding the role they play in the black hole ecosystem. One model suggests that supermassive black holes might form and grow through the merger of many IMBH, but nobody knows how common intermediate-mass black holes are in the universe. "So if we are lucky, we're going to find more free-floating black holes suddenly becoming X-ray bright because of a tidal disruption event," said Soria. "If we can do a statistical study, this will tell us how many of these IMBHs there are, how often they disrupt a star, [and] how bigger galaxies have grown by assembling smaller galaxies." RELATED STORIES — Rogue black hole spotted on its own for the first time — Astronomers may have discovered the closest black holes to Earth — Hubble Telescope sees wandering black hole slurping up stellar spaghetti Alas, Chandra, XMM-Newton and Hubble all have small fields of view, meaning that they only see small patches of the sky. Because we don't know where the next tidal disruption event might take place, the chances of our space telescopes looking in the right place at the right time are slim. In essence, Chandra got lucky back in 2009. Fortunately, help is now on hand. The Vera C. Rubin Observatory comes fully online later this year to begin a 10-year all-sky survey, and spotting the flares of tidal disruption events will be a piece of cake for it. Once it finds such an event, Hubble and Chandra will know where to look and can follow up on it. IMBHs have remained mostly hidden for now, but their time in the shadows is coming to an end. The findings were published on April 11 in The Astrophysical Journal.
Yahoo
04-07-2025
- Science
- Yahoo
Biting the 'Bullet': Amazing new JWST photo shows titanic collision of galaxy clusters
When you buy through links on our articles, Future and its syndication partners may earn a commission. NASA's James Webb Space Telescope (JWST) has produced a new image of the Bullet Cluster, which is a titanic collision between two individual galaxy clusters. The image, produced in conjunction with NASA's Chandra X-ray Observatory, reveals not only the location and mass of dark matter present, but also points the way toward one day figuring out what dark matter is actually made of. In the new image, we see the hot gas within the Bullet Cluster in false-color pink, detected by Chandra. The inferred location of dark matter is represented in blue (also false color), as measured by the JWST. Note that the blue and the pink are separate — what has caused the dark matter and the gas to separate, and how were astronomers able to produce this map of the material within the Bullet Cluster? Located 3.9 billion light-years away, the Bullet Cluster has been an occasionally controversial poster child for dark-matter studies. Back in 2006, the Hubble Space Telescope and the Chandra X-ray Observatory worked together to image the Bullet, showing the presence of its dark matter based on how light from more distant galaxies was being gravitationally lensed by the dark matter's mass. Collisions between galaxy clusters are the perfect laboratories for testing our ideas about dark matter, because they are nature's way of throwing together huge amounts of the stuff. This gives us a chance to test how dark matter particles interact with each other, if at all, and the degree of any interaction would be a huge clue as to the properties of the mysterious dark matter particle. Yet despite the dramatic Hubble and Chandra images, the Bullet Cluster — and, indeed, other galaxy cluster collisions — haven't always played ball. For instance, the velocities at which the sub-clusters are colliding seem too high for the standard model of cosmology to explain. Now the JWST has entered into the fray. A team led by Ph.D. student Sangjun Cha of Yonsei University in Seoul, South Korea, and professor of astronomy James Jee at both Yonsei and the University of California, Davis, have used the most powerful space telescope ever built to get a best-ever look at the Bullet Cluster. Hubble and Chandra had previously shown that, as the two individual galaxy clusters in the Bullet Cluster collided, the galaxies and their surrounding dark matter haloes had passed right through each other. This makes sense for the galaxies — the distances between them are so great that the chance of a head-on collision between any two is slim. It also suggests that the degree with which dark matter particles interact with each other — what we refer to as their collisional cross section — is small; otherwise, the interaction would have slowed the clouds of dark matter down, and we would detect it closer to where Chandra sees the hot, X-ray emitting intracluster gas. In contrast to the dark matter, these huge gas clouds can't get out of each other's way, so they slam into each other and don't progress any further. The end result is that the hot gas is found stuck in the middle of the collision, and the galaxies and dark matter belonging to each sub-cluster are found on opposite sides, having glided right through one another. "Our JWST measurements support this," Jee told "The galaxy distribution closely traces the dark matter." JWST was able to produce a better map of the distribution of matter, both ordinary and dark, in the Bullet Cluster by detecting, for the first time, the combined glow from billions of stars that have been thrown out of their galaxies and are now free-floating in the space between the galaxies in each sub-cluster. Cha and Jee's team were then able to use the light from these "intracluster stars" to trace the presence of dark matter and gain a more accurate map of its distribution in the Bullet Cluster. However, this has just raised more mysteries. The more refined map of the dark matter shows that, in the larger sub-cluster, on the left, the dark matter is arranged in an elongated, "hammerhead" shape that, according to Jee, "cannot be easily explained by a single head-on collision." This elongated mass of dark matter is resolved into smaller clumps centered on what we call the brightest cluster galaxies — giant elliptical galaxies that are the brightest galaxies in the sub-cluster located at its gravitational core. In contrast, the dark matter halo around the sub-cluster on the opposite side is smaller and more compact. Cha and Jee's team suspect that the elongated, clumpy mass of dark matter could only have formed when that particular sub-cluster, which was a galaxy cluster in its own right before the Bullet collision, underwent a similar collision and merger with another galaxy cluster billions of years before the formation of the Bullet. "Such an event would have stretched and distorted the dark-matter halo over time, resulting in the elongated morphology that we observe," said Jee. Despite the new discoveries such as this from JWST's more refined observations of the Bullet cluster, it is still not enough to resolve the issue of the collision velocities of the two sub-clusters. "Even with these updates, the required collision velocity remains high relative to expectations from cosmological simulations," said Jee. "The tension persists and remains an active area of research." RELATED STORIES — What is dark matter? — James Webb Space Telescope (JWST) — A complete guide — Astonishing 'halo' of high-energy particles around giant galaxy cluster is a glimpse into the early universe Dark matter makes up over a quarter of all the mass and energy in the universe, and roughly 85% of all matter, so figuring out its secrets, in particular its collisional cross-section and the cause of those high velocities, is going to be essential if we want to better understand this universe in which we live. Alas, the JWST observations of the Bullet Cluster alone are not enough to confirm what the collisional cross-section of dark matter must be. However, they do tighten the estimate of the upper limit for the value of the cross-section, constraining the list of possibilities. Astronomers are already in the process of rigorously measuring as many galaxy cluster collisions as possible, seen from all angles and distances, to try and constrain this value further. Gradually, we'll be able to rule out different models for what dark matter could be, until we're left with just a few. Coupled with experimental data from direct dark matter searches from detectors deep underground, such as the LUX-ZEPLIN experiment at the Sanford Underground Research Facility in South Dakota, we could soon be on the cusp of answering one of science's greatest mysteries: what is dark matter? The JWST observations were reported on June 30 in The Astrophysical Journal Letters.
Yahoo
28-06-2025
- Science
- Yahoo
Listen to the Andromeda galaxy's stars played as musical notes in eerie NASA video
When you buy through links on our articles, Future and its syndication partners may earn a commission. The Andromeda galaxy's spiralling stars are played as musical notes in a new NASA observatory video, creating a cosmic crescendo that's out of this world. The sonification video, released by NASA's Chandra X-ray Observatory, combines observations of the Andromeda galaxy collected by some of the world's most powerful telescopes, according to a NASA statement. Chandra also released a spectacular composite image of the galaxy, which is the closest spiral galaxy to our own Milky Way. Researchers created the composite image by stacking photos taken in different light wavelengths, merging radio, infrared, optical, ultraviolet and X-ray data. The researchers then converted those images to sound by assigning a separate range of notes to each of these wavelengths. In the video, a line passes across the lights, playing each assigned note like keys on a piano. "Musical notes ring out when the line encounters light," a representative for NASA wrote in the statement. "The lower the wavelength energy, the lower the pitches of the notes. The brighter the source, the louder the volume." NASA described the composite image as a tribute to pioneering astronomer Vera Rubin, who studied Andromeda. The tribute comes days after a new observatory named after Rubin released its first images. The Vera C. Rubin Observatory features the world's largest digital camera and will spend the next decade creating a time-lapse movie of the universe. Related: 6 incredible objects hidden in Vera C. Rubin Observatory's mind-boggling first image Andromeda, or Messier 31 (M31), is located around 2.5 million light-years from the Milky Way. Studying the galaxy has led to many scientific discoveries. For example, Rubin and her colleagues' observations of Andromeda led them to conclude that there must be an unseen matter influencing how its spiral arms rotate, according to the statement. The research was pivotal in furthering scientists' understanding of dark matter, an enigmatic non-luminous substance that shapes the universe. Researchers created the new image and soundscape of Andromeda by combining different data collected over many years. For example, the X-ray image comes from data collected by Chandra and the European Space Agency's X-ray Multi-Mirror Mission (XMM-Newton). Researchers used this data to identify high-energy radiation around the supermassive black hole at the heart of Andromeda, according to the statement. RELATED STORIES —Monster black hole jet from the early universe is basking in the 'afterglow' of the Big Bang —'This doesn't appear in computer simulations': Hubble maps chaotic history of Andromeda galaxy, and it's nothing like scientists expected —James Webb telescope unveils largest-ever map of the universe, spanning over 13 billion years The images and sounds aren't just for fun. They are another way of examining Andromeda, and therefore a learning opportunity. Andromeda offers a view of a spiral galaxy that we can't get from the Milky Way, given we're inside it, and so studying Andromeda furthers researchers' understanding of our own spiral galaxy, according to the statement. "This collection helps astronomers understand the evolution of the Milky Way, our own spiral galaxy, and provides a fascinating insight into astronomical data gathering and presentation," the NASA representative wrote.
Yahoo
26-06-2025
- Science
- Yahoo
NASA offers dazzling new sights (and sounds) of the Andromeda galaxy
Even a century after Edward Hubble confirmed its existence, astronomers learn new details about the Andromeda galaxy that help us better understand our cosmic neighborhood and the wider universe. Earlier this week, NASA released its latest detailed images of the Milky Way's spiral sibling, as well an ethereal sonification of its energy wavelengths. Attaining an outside view of the Milky Way galaxy is a bit like trying to examine the entire planet from your backyard—that is to say, it's impossible from humanity's current vantage point. The next best option for astronomers is gazing at similar nearby spiral galaxies, the closest of which is Messier 31. Also known as Andromeda, the Milky Way's most immediate neighbor is about 2.5 million light-years away, and provides an excellent option for studying how spiral galaxies form and evolve over time. It's also where a team led by astronomer Vera Rubin first detected the anomalous material now known as 'dark matter' in the 1960s. The newest glimpses at Andromeda are based on composite data collected by an international array of the world's most powerful telescopes, including the Chandra X-ray Observatory, the ESA's XMM-Newton, and even optical information from a pair of astrophotographers. The various kinds of light span the visible, infrared, radio, and ultraviolet wavelengths. When layered, they depict a vibrant and active galaxy reminiscent of our own—and the information is already helping experts expand on Andromeda's ongoing life story. 'For example, Chandra's X-rays reveal the high-energy radiation around the supermassive black hole at the center of M31 as well as many other smaller compact and dense objects strewn across the galaxy,' NASA explained in its announcement. Astronomers aren't limited to studying visual representations of Andromeda's energy; they can also assess them through sound. In addition to the images, NASA researchers compiled the galaxy datasets into a sonification by separating out each wavelength, rotating them, and stacking them on top of one another in order of their frequency. From top to bottom, that means X-rays, ultraviolet, optical, infrared, and finally radio waves. These are next assigned a range of corresponding notes, with brightness designating volume while spectrum location determines pitch. The result is a dreamlink chorus of tones as the space telescopes traverse Andromeda's 152,000 light-year diameter. There's still an untold wealth of information to learn from the Milky Way's neighbor, possibly even the means to finally understand the dark matter first detected by Rubin. That's at least what NASA hopes to achieve with the upcoming Nancy Grace Roman Space Telescope currently scheduled to go into operation in 2027.
BBC News
06-06-2025
- Science
- BBC News
ASKAP J1832: Scientists discovers mysterious pulsating star in space
Scientists say they've spotted a mysterious object in space behaving in a very strange star, which has been named ASKAP J1832, is acting unlike anything seen before, according to Nasa around 15,000 light years from Earth, it is pulsing every 44 even more strange is that it is doing it with both radio waves and X-rays. What did scientists find? A team of astronomers looked at data from Nasa's space-based Chandra X-ray Observatory and the Square Kilometre Array Pathfinder (ASKAP) radio telescope in Australia to study the discovered object, which has been called ASKAP found that the star belongs to a class of objects called "long period radio transients" - that means it sends out radio waves of different levels over tens of minutes - in this case every 44 they also found that it is also sending X-rays every 44 minutes to Nasa, this combination of factors is "unlike anything astronomers have seen in the Milky Way galaxy."Experts are trying to work out what type of object ASKAP J1832, however they think it might be one of two could be a magnetar - which is a neutron star with an extremely strong magnetic field, with an age of more than half a million it could also be possibly an unusual white dwarf star which has a companion star.
