An international team of astronomers has discovered a previously unknown major concentration of galaxies in the constellation Vela, which they have dubbed the Vela supercluster. The gravitational attraction from this large mass concentration in our cosmic neighbourhood may have an important effect on the motion of our Local Group of galaxies.
Five years ago, the Nobel Prize in Physics was awarded to three astronomers for their discovery, in the late 1990s, that the universe is expanding at an accelerating pace. Now, a team of scientists led by Professor Subir Sarkar of Oxford University’s Department of Physics has cast doubt on this standard cosmological concept.
The universe is expanding uniformly according to research led by University College London (UCL). The researchers studied the cosmic microwave background (CMB) which is the remnant radiation from the Big Bang. It shows the universe expands the same way in all directions, supporting the assumptions made in cosmologists’ standard model of the universe.
The National Science Foundation has approved funding to expand the Hydrogen Epoch of Reionisation Array (HERA) in South Africa. Upgrading the number of antennas from 19 to 240 by the year 2018 will enable HERA to study more clearly the impact of cosmic dawn, the moment a few hundred million years after the Big Bang when the first stars and galaxies blazed awake.
ESA’s Planck satellite has revealed that the first stars in the universe started forming later than previous observations of the Cosmic Microwave Background indicated. This new analysis also shows that these stars were the only sources needed to account for reionising atoms in the cosmos, having completed half of this process when the universe had reached an age of 700 million years.
Hundreds of scientists from the Sloan Digital Sky Survey III (SDSS-III) collaborated to make the largest-ever, three-dimensional map of distant galaxies. The astronomers then used this map to make one of the most precise measurements yet of the dark energy currently driving the accelerated expansion of the universe.
When Edwin Hubble discovered nearly 100 years ago that the universe was uniformly expanding in all directions, the finding was a big surprise. Then, in the mid-1990s, another shocker occurred: astronomers found that the expansion rate was accelerating, perhaps due to “dark energy.” Now, the latest measurements of our runaway universe suggest that it is expanding faster than astronomers thought.
Galaxies reached their busiest star-making pace about 11 billion years ago, then slowed down. Scientists have puzzled for years over the question of what happened. Now researchers have found evidence supporting the argument that the answer was energy feedback from quasars within the galaxies where stars are born.
Astronomers have used NASA’s Chandra X-ray Observatory to discover a jet from a very distant supermassive black hole being illuminated by the oldest light in the universe. This discovery shows that black holes with powerful jets may be more common than previously thought in the first few billion years after the Big Bang.