Researchers have found a large population of distant dwarf galaxies that could reveal important details about a productive period of star formation in the universe billions of years ago. It is believed that dwarf galaxies played a significant role during the so-called reionisation era in transforming the dark early universe into one that is bright, ionised and transparent.
Researchers who are looking for new ways to probe the nature of gravity and dark energy in the universe have adopted a new strategy: looking at what’s not there. An international team of astronomers were able to achieve four times better precision in measurements of how the universe’s visible matter is clustered together by studying the empty spaces in between.
Researchers at the University of Cambridge have developed a new method for detecting and measuring one of the most powerful, and most mysterious, events in the universe — a black hole being kicked out of its host galaxy and into intergalactic space at speeds as high as 5,000 kilometres per second (11 million miles per hour).
Some galaxies pump out vast amounts of energy from a very small volume of space, typically not much bigger than our own solar system. The cores of so-called active galactic nuclei (AGNs) can be billions of light-years away, so are difficult to study in any detail. However, natural gravitational ‘microlenses’ can provide a way to probe these objects.
Research teams on both sides of the Atlantic have ditched software approximations and found that small-scale structures produce important effects using new computer codes. Precise modelling of the cosmos using Einstein’s full theory of general relativity will change our detailed understanding of evolution in the universe and the growth of structure within it.
A European team of astronomers have used the new GRAVITY instrument at ESO’s Very Large Telescope to obtain exciting observations of the centre of the Milky Way by combining light from all four of the 8.2-metre Unit Telescopes for the first time. These results provide a taste of the groundbreaking science that GRAVITY will produce as it tests Einstein’s general relativity.
Three months after announcing the first detection of gravitational waves, scientists report a second observation of the merger of two black holes made on 26 December 2015. The scientists were able to infer that the mass of the black holes was between 8 and 14 solar masses and the event took place at a distance of about 1.4 billion light-years from Earth.
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.
Using data from the 8.2-metre Subaru Telescope, an international team led by Japanese researchers has made a 3-D map of 3,000 galaxies 13 billion light-years from Earth. Based on this comprehensive survey — the first such study at this great distance — the team was able to confirm that Einstein’s general theory of relativity is still valid.
Subtle distortions hidden in a stunning Atacama Large Millimetre/submillimetre Array (ALMA) image of the gravitational lens SDP.81 are telltale signs that a dwarf dark galaxy is lurking in the halo of a much larger galaxy nearly 4 billion light-years away. This discovery could help astronomers address important questions on the nature of dark matter.