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Categories: Paleontology: Early Mammals and Birds, Space: Cosmology
Published Astrophysicists confirm the faintest galaxy ever seen in the early universe
(via sciencedaily.com) Original source After the Big Bang, the universe expanded and cooled sufficiently for hydrogen atoms to form. In the absence of light from the first stars and galaxies, the universe entered a period known as the cosmic dark ages. The first stars and galaxies appeared several hundred million years later and began burning away the hydrogen fog left over from the Big Bang, rendering the universe transparent, like it is today. Researchers have now confirmed the existence of a distant, faint galaxy typical of those whose light burned through the hydrogen atoms; the finding should help them understand how the cosmic dark ages ended.
Published X-ray emissions from black hole jets vary unexpectedly, challenging leading model of particle acceleration
(via sciencedaily.com) Original source Black hole jets are known to emit x-rays, but how they accelerate particles to this high-energy state is still a mystery. Surprising new findings appear to rule out a leading theory, opening the door to reimagining how particle acceleration works. One model of how jets generate x-rays expects the jets' x-ray emissions to remain stable over long time scales. However, the new paper found that the x-ray emissions of a statistically significant number of jets varied over just a few years.
Published Helium nuclei research advances our understanding of cosmic ray origin and propagation
(via sciencedaily.com) Original source The latest observations from Low Earth Orbit with the International Space Station provide further evidence of spectral hardening and softening of cosmic ray particles.
Published Dinosaurs were the first to take the perspectives of others
(via sciencedaily.com) Original source Understanding that others hold different viewpoints from your own is essential for human sociality. Adopting another person's visual perspective is a complex skill that emerges around the age of two. A new study suggests that this ability first arose in dinosaurs, at least 60 million years before it appeared in mammals. These findings challenge the idea that mammals were the originators of novel and superior forms of intelligence in the wake of the dinosaur extinction.
Published Fossils of a saber-toothed top predator reveal a scramble for dominance leading up to 'the Great Dying'
(via sciencedaily.com) Original source A tiger-sized saber-toothed creature called Inostrancevia has previously only been found in Russia. But scientists have discovered its fossils in South Africa, suggesting that it migrated 7,000 miles across the supercontinent Pangaea during the world's worst mass extinction 252 million years ago. Heading to South Africa allowed it to fill a gap in a faraway ecosystem that had lost its top predators.
Published An X-ray look at the heart of powerful quasars
(via sciencedaily.com) Original source Researchers have observed the X-ray emission of the most luminous quasar seen in the last 9 billion years of cosmic history, known as SMSS J114447.77-430859.3, or J1144 for short. The new perspective sheds light on the inner workings of quasars and how they interact with their environment.
Published Radio signal reveals supernova origin
(via sciencedaily.com) Original source Astronomers reveal the origin of a thermonuclear supernova explosion. Strong emission lines of helium and the first detection of such a supernova in radio waves show that the exploding white dwarf star had a helium-rich companion.
Published Researcher uses mammal DNA to zoom into the human genome with unprecedented resolution
(via sciencedaily.com) Original source Scientists have precisely identified base pairs of the human genome that remained consistent over millions of years of mammalian evolution, and which play a crucial role in human disease. The team analyzed the genomes of 240 mammals, including humans and identified base pairs that were 'constrained' -- meaning they remained generally consistent -- across mammal species over the course of evolution. The most constrained base pairs in mammals were over seven times more likely to be causal for human disease and complex trait, and over 11 times more likely when researchers looked at the most constrained base pairs in primates alone.
Published Astronomers reveal the largest cosmic explosion ever seen
(via sciencedaily.com) Original source Astronomers have uncovered the largest cosmic explosion ever witnessed. The explosion is more than ten times brighter than any known supernova and three times brighter than the brightest tidal disruption event, where a star falls into a supermassive black hole.
Published Researchers find new approach to explore earliest universe dynamics with gravitational waves
(via sciencedaily.com) Original source Researchers have discovered a new generic production mechanism of gravitational waves generated by a phenomenon known as oscillons.
Published Hidden supermassive black holes brought to life by galaxies on collision course
(via sciencedaily.com) Original source Astronomers have found that supermassive black holes obscured by dust are more likely to grow and release tremendous amounts of energy when they are inside galaxies that are expected to collide with a neighbouring galaxy.
Published Celestial monsters at the origin of globular clusters
(via sciencedaily.com) Original source Globular clusters are the most massive and oldest star clusters in the Universe. They can contain up to 1 million of them. The chemical composition of these stars, born at the same time, shows anomalies that are not found in any other population of stars. Explaining this specificity is one of the great challenges of astronomy. After having imagined that supermassive stars could be at the origin, a team believes it has discovered the first chemical trace attesting to their presence in globular proto-clusters, born about 440 million years after the Big Bang.
Published Measurement of the Universe's expansion rate weighs in on a longstanding debate in physics and astronomy
(via sciencedaily.com) Original source A team used a first-of-its-kind technique to measure the expansion rate of the Universe, providing insight that could help more accurately determine the Universe's age and help physicists and astronomers better understand the cosmos.
Published Neutron star's X-rays reveal 'photon metamorphosis'
(via sciencedaily.com) Original source A 'beautiful effect' predicted by quantum electrodynamics (QED) can explain the puzzling first observations of polarized X-rays emitted by a magnetar -- a neutron star featuring a powerful magnetic field, according to an astrophysicist.
Published New tusk-analysis techniques reveal surging testosterone in male woolly mammoths
(via sciencedaily.com) Original source Traces of sex hormones extracted from a woolly mammoth's tusk provide the first direct evidence that adult males experienced musth, a testosterone-driven episode of heightened aggression against rival males, according to a new study.
Published Astronomers find distant gas clouds with leftovers of the first stars
(via sciencedaily.com) Original source Using ESO's Very Large Telescope (VLT), researchers have found for the first time the fingerprints left by the explosion of the first stars in the Universe. They detected three distant gas clouds whose chemical composition matches what we expect from the first stellar explosions. These findings bring us one step closer to understanding the nature of the first stars that formed after the Big Bang.
Published New research redefines mammalian tree of life
(via sciencedaily.com) Original source Scientists from around the globe are using the largest mammalian genomic dataset in history to determine the evolutionary history of the human genome in the context of mammalian evolutionary history. Their ultimate goal is to better identify the genetic basis for traits and diseases in people and other species.
Published Information 'deleted' from the human genome may be what made us human
(via sciencedaily.com) Original source What the human genome is lacking compared with the genomes of other primates might have been as crucial to the development of humankind as what has been added during our evolutionary history, according to a new study led by researchers at Yale and the Broad Institute of MIT and Harvard. The new findings, published April 28 in the journal Science, fill an important gap in what is known about historical changes to the human genome.
Published Mammalian evolution provides hints for understanding the origins of human disease
(via sciencedaily.com) Original source Even though it is important to know where these variations are located in the genome, it's also useful to know how or why these genetic variations happened in the first place.
Published Most massive touching stars ever found will eventually collide as black holes
(via sciencedaily.com) Original source A new study looked at a known binary star (two stars orbiting around a mutual center of gravity), analyzing starlight obtained from a range of ground- and space-based telescopes. The researchers found that the stars, located in a neighboring dwarf galaxy called the Small Magellanic Cloud, are in partial contact and swapping material with each other, with one star currently 'feeding' off the other. They orbit each other every three days and are the most massive touching stars (known as contact binaries) yet observed.