active galactic nuclei – Astronomy Now

M77 sheds light on differences between active galactic nuclei

22 February 2022 Astronomy Now

New observations support the idea that active galactic nuclei, despite their different appearances, share the same basic structure.

Two galaxies with active galactic nuclei interact in dramatic fashion

13 February 2022 Astronomy Now

Hubble captures a dramatic view of two galaxies, both with active galactic nuclei, interacting in a close encounter that is pulling gas, dust and entire star systems from one toward the other.

Dust clouds may explain emissions from active galactic nuclei

18 June 2018 Astronomy Now

Changes in the light emerging from active galactic nuclei, powered by supermassive black holes, may be explained by clouds of intervening dust that can dim and redden the radiation, eliminating the need for more exotic explanations.

Merging galaxies have enshrouded black holes

10 May 2017 Astronomy Now

Black holes get a bad rap in popular culture for swallowing everything in their environments. In reality, stars, gas and dust can orbit black holes for long periods of time, until a major disruption pushes the material in.

Starvation diet for supermassive black hole dims brilliant galaxy

10 November 2016 Astronomy Now

Astronomers may have solved the mystery of the peculiar volatile behaviour of a supermassive black hole at the centre of a galaxy known as Markarian 1018 some 590 million light-years away. Combined data from NASA’s Chandra X-ray Observatory and other observatories suggest that the black hole is no longer being fed enough fuel to make its surroundings shine brightly.

Chance microlensing events enable astronomers to probe distant quasars

1 July 2016 Astronomy Now

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.

Telescopes combine to push frontier on galaxy clusters

12 March 2016 Astronomy Now

Galaxy clusters are enormous collections of hundreds or even thousands of galaxies and vast reservoirs of hot gas embedded in massive clouds of dark matter. To learn more about clusters, including how they grow via collisions, astronomers have used some of the world’s most powerful X-ray, optical and radio telescopes. The name for this galaxy cluster project is the “Frontier Fields”.

Merging galaxies break radio silence

29 May 2015 Astronomy Now

A large Hubble survey confirms an unambiguous link between the presence of supermassive black holes that power high-speed, radio-signal-emitting jets and the merger history of their host galaxies. The results lend significant weight to the case for jets being the result of merging black holes.

Supermassive black hole blasts star-making gas from galaxy’s core

26 March 2015 Astronomy Now

Many galaxies blast huge, wide-angled flows of material outward from their centres, pushing to their outer edges enough dust and gas each year that otherwise would have formed more than a thousand stars the size of our Sun. A team led by University of Maryland scientists has found the driving force behind these massive molecular outflows.