All posts tagged: X-ray astronomy

Powerful black hole pushes quasar’s winds across 300,000 light-years

Powerful black hole pushes quasar’s winds across 300,000 light-years

Published by Jenni Sidey

A quasar 3.4 billion light-years away is stirring hot gas across roughly 300,000 light-years, far beyond the galaxy that contains it. XRISM detected unusually fast gas motions carrying about 100 times more energy than earlier estimates for similar black-hole winds. The observations may help astronomers improve models of how black holes influence galaxy clusters, though turbulence, gas flows and sloshing remain difficult to separate. A quasar 3.4 billion light-years away is stirring hot gas far beyond its home galaxy, sending energy through a region 300,000 light-years wide. The disturbance is forcing astronomers to rethink how far black-hole winds can reach. The source is H1821+643, a bright quasar in the constellation Draco. At its center sits a supermassive black hole about 2.6 billion times the mass of the sun. It shines far more powerfully than most nearby quasars despite weak radio jets. “Black holes are largely known for sucking matter in, but they also eject gas in the form of powerful winds,” said Satoshi Yamada, an assistant professor at Tohoku University’s Frontier Institute for Interdisciplinary Sciences. …

First x-rays captured in space mark breakthrough for astronaut health

First x-rays captured in space mark breakthrough for astronaut health

Published by Jenni Sidey

Medical care in space has long faced a quiet but serious limitation. For more than 40 years, astronauts relied on ultrasound as their only imaging tool. While useful, it cannot answer every question when something goes wrong. Now, a new study shows a major step forward. Crew members aboard a commercial spaceflight have captured the first diagnostic X-rays in orbit. The results suggest that a simple, portable device could transform how health and safety are managed in space. A Longstanding Gap In Space Medicine Space travel places the human body under strain. Bones weaken, fluids shift, and injuries become harder to diagnose. As missions grow longer, risks increase. Ultrasound has served as the main imaging tool because it is compact and safe. Still, it has limits. It depends heavily on operator skill and cannot always detect fractures or lung problems. Preflight, in-flight, and postflight nonmedical radiographs. (CREDIT: Radiology) Dr. Sheyna Gifford, lead researcher and assistant professor of aerospace medicine at Mayo Clinic, explained the challenge. “It’s been a dream for aerospace medicine to have more …

XMM-Newton gamma-ray detection shows the Milky Way is bigger than previously thought

XMM-Newton gamma-ray detection shows the Milky Way is bigger than previously thought

Published by Jenni Sidey

The Milky Way’s farthest spiral arms have long been sketched more from motion than measurement. Now three violent explosions far beyond our galaxy have helped redraw that map, showing that parts of the outer Milky Way sit farther away than astronomers thought. The work used the fading X-ray afterglow of three gamma-ray bursts, brief but extraordinarily bright blasts that erupted in distant galaxies. As that X-ray light crossed the Milky Way, some of it scattered off dust in the galaxy’s spiral arms, creating expanding rings that space telescopes could track. Those rings, the team found, offer a rare direct way to measure remote stretches of the galactic disk. That matters because getting your bearings inside the Milky Way is hard. Earth sits buried in the galaxy’s disk, not above it, and thick dust clouds block many lines of sight. Astronomers have built galactic maps using tracers such as hydrogen gas, carbon monoxide, giant molecular clouds, H II regions, and methanol masers, but distances in the outer galaxy often depend on models of how the Milky …

Student astronomer discovers rare white dwarf star feeding on a red dwarf companion

Student astronomer discovers rare white dwarf star feeding on a red dwarf companion

Published by Jenni Sidey

ASKAP J1745-5051 did not look like an easy answer to anything. It flashed radio waves every 1.4 hours, then went quiet for stretches. Then it lit up again with a pattern astronomers had trouble classifying. That odd behavior has now helped pin down one of astronomy’s stranger new mysteries. In a study published in Nature Astronomy, an international team reports that ASKAP J1745-5051 is a compact binary system. In this system, a white dwarf is pulling material from a low-mass red dwarf companion. The finding offers some of the strongest evidence yet that at least some long-period radio transients come from white dwarf binaries. Previously, many had suspected they came from slowly spinning neutron stars. The system was first spotted in an untargeted search for circularly polarized radio sources with the Australian Square Kilometre Array Pathfinder, or ASKAP. Additionally, follow-up observations with MeerKAT sharpened its position. Astronomers matched it to a faint optical source in Gaia data. What they found next changed the story. Artist’s impression of the white dwarf binary ASKAP J1745-5051. The smaller, …

Gamma Cassiopeiae may be hiding a magnetic white dwarf companion

Gamma Cassiopeiae may be hiding a magnetic white dwarf companion

Published by Jenni Sidey

Visible without a telescope, γ Cassiopeiae has stood out for decades because it behaves unlike an ordinary massive star. Its X-rays are far too intense, far too hot, and far too erratic. Now, a team led by astronomers at the University of Liège says those X-rays do not come from the star itself. They come from a white dwarf circling it. The finding, published in Astronomy and Astrophysics, could do more than explain one strange object. It may also confirm a long-predicted class of binary star systems that had remained frustratingly hard to pin down. γ Cas was the first Be star identified, back in 1866 by Italian astronomer Angelo Secchi. Be stars spin rapidly and throw off material that forms a disc around them. But in 1976, astronomers noticed something odd: γ Cas was emitting X-rays about 40 times stronger than similar massive stars, with plasma heated to more than 100 million degrees. That made it an outlier. Later observations found around two dozen similar objects, now known as γ Cas analogues. Illustration of …