After a series of upgrades, the twin detectors of LIGO, the Laser Interferometer Gravitational-wave Observatory, have turned back on and resumed their search for ripples in the fabric of space and time known as gravitational waves. Now boasting a 25 percent improvement in sensitivity, LIGO recommenced science observations at 4pm GMT on 30 November.
Gamma-ray bursts, or GRBs, are some of the most violent and energetic events in the universe. Although these events are the most luminous explosions astronomers can observe, a new study using NASA’s Chandra X-ray Observatory, NASA’s Swift satellite and other Earth-based telescopes suggests that scientists may be missing a majority of these powerful cosmic detonations.
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 matter of scientific speculation since the 1930s, dark matter itself cannot yet be detected, but its gravitational effects can be. Now, eight scientists from Johns Hopkins University consider the possibility that the first black hole binary detected by LIGO could be part of this mysterious substance known to make up about 85 percent of the mass of the universe.
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.
LISA Pathfinder, a mission led by the European Space Agency with contributions from NASA, has successfully tested key technology needed to build a space-based observatory for detecting gravitational waves. These tiny ripples in the fabric of space, predicted by Albert Einstein a century ago, were first seen last year by the ground-based Laser Interferometer Gravitational-Wave Observatory (LIGO).
Dark matter is a mysterious substance composing most of the material universe, now widely thought to be some form of massive exotic particle. An intriguing alternative view is that dark matter is made of black holes formed during the first second of our universe’s existence, known as primordial black holes.
On 14 September 2015, gravitational waves produced by a pair of merging black holes gently rattled space-time in the vicinity of Earth. Less than half a second later, NASA’s Fermi Gamma-ray Space Telescope picked up a brief, weak burst of high-energy light consistent with the same part of the sky. Analysis of this burst suggests that the events are connected.
New results from NANOGrav — the North American Nanohertz Observatory for Gravitational Waves — establish astrophysically significant limits in the search for low-frequency gravitational waves. This result provides insight into how often galaxies merge and how those merging galaxies evolve over time.
On 14 September 2015, the Laser Interferometer Gravitational-wave Observatory (LIGO) detected gravitational waves from the merger of two black holes 29 and 36 times the mass of the Sun. New research suggests that the two black holes might have resided inside a single, massive star whose death generated a gamma-ray burst detected by the Fermi Space Telescope.