How monster black holes are kept in check by 220,000,000mph streams of plasma

How monster black holes are kept in check by 220,000,000mph streams of plasma - Black holes – and indeed the galaxies they’re found in – are reined in by huge streams of highly ionised plasma, researchers have discovered.

Francesco Tombesi from Nasa's Goddard Space Flight Center in Greenbelt, using data gathered from the European Space Agency’s XMM-Newton X-ray Observatory, has discovered that these streams, called ‘ultra-fast outflows’ exert a massive influence on the number of stars in galaxies and the size of black holes at their centre.

The study follows a baffling observation from astronomers in recent years – that there was a strong correlation between the mass of a black hole and the number of stars in the entire galaxy.

Supermassive black holes can produce narrow particle jets (orange) and wider streams of gas (blue-grey) known as ultra-fast outflows, which are powerful enough to regulate both star formation in the wider galaxy and the growth of the black hole

Massive black holes appear to reside in galaxies that contain more stars and that also move faster.

It was puzzling because the gravitational influence of a black hole shouldn’t be able to cover a whole galaxy.

What Tombesi and his colleagues believe, is that blue-grey ultra-fast outflows that emanate from a black hole’s accretion disk - million-degree gas that encircles it – could be responsible.

Tombesi said: ‘We call them ultra-fast outflows, or UFOs, because their velocities are very large – between 10 000 and 100 000 kilometres per second (around 220,000,000mph). With these mildly-relativistic velocities, UFOs are much faster, hence much more powerful, than other, ordinary galactic outflows, although they are still slower than relativistic jets.’

‘The outflows studied in our work exert a more intense feedback on the host galaxy than do jets. Since they are more massive, slower and have wider opening angles, they are bound to interact more significantly with the interstellar medium.’

Star gazing: The researchers studied 42 galaxies in their study of ultra-fast outflows

These 'feedback mechanisms' may be able to quench star formation and the growth of the black hole at the same time.

Tombesi believes that supermassive black holes initially help vast amounts of stars to form in galaxies, but that the UFOs act a bit like a cosmic stopper.

He told MailOnline: 'As soon as the black hole reached a certain mass, the feedback induced by its outflows was strong enough to clear away the remaining gas and quench both its growth and the formation of new stars.

'The effect of feedback acts more in a way of stopping these growth processes, establishing an upper limit on both the black hole mass and star formation in the bulge.'

The XMM-Newton X-ray Observatory was used to scrutinise 42 galaxies, with 40 per cent of them containing ultra-fast outflows.

Tombesi added: ‘We intend now to focus on figuring out the detailed physical mechanisms that generate the outflows in the first place. This will represent a further, valuable step towards a full understanding of how active galaxies work and evolve.’ ( dailymail.co.uk )