Hubble Space Telescope observations have taken advantage of gravitational lensing to reveal the largest sample of the faintest and earliest known galaxies in the universe, formed just 600 million years after the Big Bang. Astronomers have determined, for the first time with some confidence, that these small galaxies were vital to creating the universe that we see today.
When a star collapses forming a black hole, a space-time singularity is created wherein the laws of physics no longer work. In 1965, Sir Roger Penrose presented a theorem where he associated that singularity with so-called ”trapped surfaces” that shrink over time. That hypothesis — one of the results of the general theory of relativity — is now celebrating its 50th anniversary.
Astronomers using NASA’s Chandra X-ray Observatory and the 6.5-metre Clay Telescope in Chile have identified the smallest supermassive black hole ever detected in the centre of a galaxy. This oxymoronic object could provide clues to how larger black holes formed along with their host galaxies 13 billion years or more in the past.
An international team of astronomers studying more than 200,000 galaxies has made the most comprehensive assessment of the energy output of the nearby universe. The Galaxy And Mass Assembly (GAMA) project confirms that the energy produced is only about half what it was two billion years ago and this fading is occurring across all wavelengths from the ultraviolet to the far infrared. The universe is slowly dying.
EGSY8p7 is the most distant confirmed galaxy whose spectrum obtained with the W. M. Keck Observatory places it at a redshift of 8.68, at a time when the universe was less than 600 million years old. Hydrogen emission from EGSY8p7 may indicate it is the first known example of an early generation of young galaxies emitting unusually strong radiation.
The chemical element lithium is predicted to have been created by the Big Bang, 13.8 billion years ago. Observations of Nova Centauri 2013 show that lithium has been found for the first time in material ejected by a nova, helping to explain the mystery of why many young stars seem to have more of this chemical element than expected.
The Atacama Large Millimetre/submillimetre Array (ALMA) has been used to detect the most distant clouds of star-forming gas yet found in normal galaxies in the early universe. The new observations allow astronomers to start to see how the first galaxies were built up and how they cleared the cosmic fog during the era of reionisation.
Astronomers have spotted a super-sized black hole in the early universe that grew much faster than its host galaxy. The discovery challenges previous notions about the way host galaxies grow in relation to black holes and casts doubt on earlier suggestions that the radiation emitted by expanding black holes curtails the creation of stars.
In his second report from the Royal Astronomical Society’s National Astronomy Meeting 2015, Kulvinder Singh Chadha ponders the nature of dark matter and whether cosmic jets — jets of material from active galaxies travelling close to the speed of light — may correlate with dense regions of dark matter in the Universe.
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