An international team led by the University of Geneva (UNIGE) has identified three ultra-massive galaxies—nearly as massive as the Milky Way—already in place within the first billion years after the Big Bang.
Category: cosmology – Page 40
A black hole in the MAXI J1820+070 system ejected about 400 million billion pounds of gas in twin jets—equivalent to 500 million times the mass of the Empire State Building.
In a significant astronomical discovery, NASA’s Chandra X-ray Observatory captured a rare phenomenon: a black hole ejecting massive jets of material at nearly the speed of light. This black hole is part of the binary system MAXI J1820+070, positioned approximately 10,000 light-years away, which is relatively close in cosmic terms. This proximity allowed detailed observations that contribute to our understanding of how black holes interact with companion stars.
The MAXI J1820+070 system features a black hole about eight times the mass of the sun, drawing material from a companion star roughly half the sun’s mass. This process creates an accretion disk—a luminous sphere emitting bright X-rays as material is funneled toward the black hole. While some gas is absorbed, some is expelled in powerful jets that travel in opposite directions.
Astronomers have found a supermassive black hole ejecting a jet of energy at nearly the speed of light. This event, called AT2022cmc, is the most distant tidal disruption event (TDE) ever recorded, taking place 12.4 billion light years away from Earth. The international team of researchers shared their findings in papers published on November 30 in Nature and Nature Astronomy, noting that this TDE was observable due to the intense brightness of its jet and the direction it pointed—right toward Earth.
Igon Andreoni, an astronomer at the University of Maryland and co-leader of the study, emphasized how unusual it is to witness such a jet, as it must be aimed almost directly at Earth for detection. The light from AT2022cmc reached Earth after traveling across space for approximately 8.5 billion years, implying that this event happened when the universe was just a third of its current age.
The observation has led researchers to propose that the black hole involved was spinning at a high rate, which likely contributed to the formation of the jet. Despite its classification as “supermassive,” this black hole’s mass, estimated at a few hundred million times that of the Sun, is typical for black holes at the centers of galaxies.
Physicists show that neutron stars may be shrouded in clouds of ‘axions’ — and that these clouds can teach us a lot. A team of physicists from the universities of Amsterdam, Princeton and Oxford have shown that extremely light particles known as axions may occur in large clouds around neutron stars. These axions could form an explanation for the elusive dark matter that cosmologists search for — and moreover, they might not be too difficult to observe.
Massive stars about eight times more massive than the sun explode as supernovae at the end of their lives. The explosions, which leave behind a black hole or a neutron star, are so energetic they can outshine their host galaxies for months. However, astronomers appear to have spotted a massive star that skipped the explosion and turned directly into a black hole.
The Large Hadron Collider (LHC) is like an immensely powerful kitchen, designed to cook up some of the rarest and hottest recipes in the universe, like the quark–gluon plasma, a state of matter known to have existed shortly after the Big Bang. While the LHC mostly collides protons, once a year it collides heavy ions—such as lead nuclei—a key ingredient for preparing this primordial soup.
A new statistical analysis by researchers at the University of Arizona suggests that color vision evolved in animals around 500 million years ago, long before the evolution of colorful fruits and flowers, which started sprouting 200 to 350 million years ago. The researchers focused on what they term “conspicuous colors”—basically, the ones kids are likeliest to select in a 16 pack of Crayolas—red, orange, yellow, blue and purple.
Around 150 million years ago, presumably to capitalize on the well-established prevalence of color vision, species began evolving warning coloration. And 50 million years later, there was an evolutionary explosion of both warning and sexual coloration. Although the reasons behind this evolutionary burst are still unclear, the researchers identified three warning signal animal vectors behind it: ray-finned fishes, birds and lizards.
Additionally, warning coloration is much more widespread among species than sexual coloration, likely because colorful animals do not themselves need to have color vision to signal the danger they pose to other, color-sensitive species. Sexual color signals, on the other hand, are confined to vertebrate and arthropod species that have well-developed color vision.
Primordial black holes may be exploding throughout the universe. If we can catch them in the act, it could pave the way to new physics, a study suggests.
Scientists recently reported a monumental discovery in astrophysics: the detection of low-frequency gravitational waves. This breakthrough was made by NANOGrav (North American Nanohertz Observatory for Gravitational Waves), which released findings in The Astrophysical Journal Letters. These waves, predicted by Einstein, are generated when massive objects like supermassive black holes interact, creating cosmic ripples across spacetime. For the first time, researchers have managed to “hear” these background vibrations of the universe, likened to the faint, low hum in a cosmic orchestra. This detection not only broadens our understanding of gravitational waves but also opens up a new chapter in studying the universe’s largest objects and events.