Quasars are actively feeding supermassive black holes, blasting so much radiation into space that they’re visible billions of light years away. These are just some of the objects that ESA’s Euclid mission is seeing as it completes its survey of the large scale structure of the Universe, measuring the influence of dark matter and dark energy over time. Recently, the mission turned up dozens of previously unseen quasars at high redshifts, including the farthest ever seen at z=7.7, seen at a time when the Universe was only 680 million years old.
Quasars are some of the most powerful objects in the universe. They’re the immensely bright cores of certain galaxies, powered by actively feeding supermassive black holes.
We typically spot quasars many billions of light-years away. And because their light has taken many billions of years to reach us, that means we usually see quasars in the universe’s early years, when there was abundant material for the black holes to feast on.
About 9 billion years ago, during one of the busiest periods in cosmic history, many massive galaxies were still building stars at a furious pace. Yet a smaller group had already slammed on the brakes. New observations from the James Webb Space Telescope suggest that, in many cases, those sudden shutdowns were not gentle. Instead, they may have followed violent collisions. These collisions left behind compact, disturbed remnants.
Far beyond Pluto, where sunlight is faint and the planets are long behind, NASA’s New Horizons spacecraft is moving through a region where the Sun’s outflow begins to lose its grip. There, a stream of charged particles called the solar wind is gradually slowing down. The new measurements help show why. The answer lies in a quiet, persistent encounter with material drifting in from interstellar space.
The vast space between galaxies is mostly empty, just a few atoms in every cubic meter, but it’s not totally empty. Now, astronomers have discovered a galaxy plowing through the intergalactic medium so quickly that it’s leaving a wake behind, stretching 1.8 million light-years long. Astronomers think the galaxy is falling into a huge cluster, traveling faster than sound can move through the hot gas, so it piles up in front like a bow wave.
Most large stars are found in binary and multiple star systems. Some of these stars are so close together; they’re orbiting one another in just a few hours. They couldn’t have formed this close together; instead, they must have formed farther apart and then migrated closer to one another. What mechanism caused this migration? A new study shows how magnetic fields can be the force that drives the inward migration in binary stars.
There’s a time early on in the Universe known as Cosmic Dawn. This is within the first few billion years after the Big Bang, when the first stars and galaxies were blazing, clearing out the cosmic fog. A new survey with Webb has looked at thousands of objects in a region that’s about three times bigger than the Moon, revealing a collection of galaxies forming within the first billion years of the Universe’s history.
In November last year, the scientific community was rocked by an extraordinary study. Opposing the widely held view that the expansion of the universe is accelerating, this paper claimed it was actually slowing down.
If true, astronomers need to rethink much of what they know about the structure of the universe, particularly the mysterious force we call dark energy.
A quasar from the universe’s first 850 million years has started to look less like a distant pinprick and more like a real physical system. By catching it flickering over time, astronomers have traced the structure of matter swirling around one of the earliest known supermassive black holes. What they found deepens one of cosmology’s biggest puzzles.