Institute of Astronomy

Astronomy News

Astronomy: Laser focus

21 January 2015 - 6:37pm

Astronomy: Laser focus

Nature 517, 7535 (2015).

Author: Ann Finkbeiner

By firing lasers into the sky, Claire Max has transformed the capabilities of current — and future — telescopes.

Japan might get to name the most alien worlds

21 January 2015 - 6:06pm
The International Astronomical Union's exoplanet-naming scheme may accidentally let Japanese astronomy clubs make the most suggestions for possible planet names

Mystery storms rage across face of Uranus

21 January 2015 - 12:15pm

In the past year, the seventh planet has sported huge cloud systems so bright they could be seen by amateur astronomers on Earth, but no one knows the cause

Probe gets an eyeful of dwarf Ceres

19 January 2015 - 7:38pm

The American space agency's Dawn spacecraft is bearing down on Ceres, the largest object in the asteroid belt between Mars and Jupiter.

Epic cosmic radio burst finally seen in real time

19 January 2015 - 9:15am
They're over in a flash, but a mega-powerful radio burst has finally been spotted in real time, rather than in old data, giving clues to their mysterious origin

Rosetta will prompt image rethink

16 January 2015 - 10:49pm

The way some images have been drip-fed from the European Space Agency's Rosetta mission at Comet 67P should prompt a rethink on data policies, the organisation's chief says.

Beagle-2 lander found on Mars

16 January 2015 - 12:54pm

The UK-led Beagle-2 Mars lander, which hitched a ride on ESA's Mars Express mission and was lost on Mars since 2003, has been found in images taken by a NASA orbiter at the Red Planet.

Lost Beagle2 probe found on Mars

16 January 2015 - 10:50am

High-resolution images taken from orbit identify the landing location of the lost Beagle2 probe, and it appears to be in one piece.

Galactic ‘hailstorm’ in the early Universe

16 January 2015 - 8:04am

Two teams of astronomers led by researchers at the University of Cambridge have looked back nearly 13 billion years, when the Universe was less than 10 percent its present age, to determine how quasars – extremely luminous objects powered by supermassive black holes with the mass of a billion suns – regulate the formation of stars and the build-up of the most massive galaxies.

Using a combination of data gathered from powerful radio telescopes and supercomputer simulations, the teams found that a quasar spits out cold gas at speeds up to 2000 kilometres per second, and across distances of nearly 200,000 light years – much farther than has been observed before.

How this cold gas - the raw material for star formation in galaxies - can be accelerated to such high speeds had remained a mystery. Detailed comparison of new observations and supercomputer simulations has only now allowed researchers to understand how this can happen: the gas is first heated to temperatures of tens of millions of degrees by the energy released by the supermassive black hole powering the quasar. This enormous build-up of pressure accelerates the hot gas and pushes it to the outskirts of the galaxy.

The supercomputer simulations show that on its way out of the parent galaxy, there is just enough time for some of the hot gas to cool to temperatures low enough to be observable with radio telescopes. The results are presented in two separate papers published today (16 January) in the journals Monthly Notices of the Royal Astronomical Society and Astronomy & Astrophysics.

Quasars are amongst the most luminous objects in the Universe, and the most distant quasars are so far away that they allow us to peer back billions of years in time. They are powered by supermassive black holes at the centre of galaxies, surrounded by a rapidly spinning disk-like region of gas. As the black hole pulls in matter from its surroundings, huge amounts of energy are released.

“It is the first time that we have seen outflowing cold gas moving at these large speeds at such large distances from the supermassive black hole,” said Claudia Cicone, a PhD student at Cambridge’s Cavendish Laboratory and Kavli Institute for Cosmology, and lead author on the first of the two papers. “It is very difficult to have matter with temperatures this low move as fast as we observed.”

Cicone’s observations allowed the second team of researchers specialising in supercomputer simulations to develop a detailed theoretical model of the outflowing gas around a bright quasar.

“We found that while gas is launched out of the quasar at very high temperatures, there is enough time for some of it to cool through radiative cooling – similar to how the Earth cools down on a cloudless night,” said Tiago Costa, a PhD student at the Institute of Astronomy and the Kavli Institute for Cosmology, and lead author on the second paper. “The amazing thing is that in this distant galaxy in the young Universe the conditions are just right for enough of the fast moving hot gas to cool to the low temperatures that Claudia and her team have found.”

Working at the IRAM Plateau De Bure interferometer in the French Alps, the researchers gathered data in the millimetre band, which allows observation of the emission from the cold gas which is the primary fuel for star formation and main ingredient of galaxies, but is almost invisible at other wavelengths.

The research was supported by the UK Science and Technology Facilities Council (STFC), the Isaac Newton Trust and the European Research Council (ERC). The computer simulations were run using the Computer Cluster DARWIN, operated by the University of Cambridge High Performance Computing Service, as part of STFCs DiRAC supercomputer facility.

Inset image: Comparison of observation and simulations. Credit: Tiago Costa

Astronomers have been able to peer back to the young Universe to determine how quasars – powered by supermassive black holes with the mass of a billion suns – form and shape the evolution of galaxies.

While gas is launched out of the quasar at very high temperatures, there is enough time for some of it to cool through radiative cooling – similar to how the Earth cools down on a cloudless nightTiago CostaTiago CostaIllustration of the outflow (red) and gas flowing in to the quasar in the centre (blue). The cold clumps shown in the inset image are expelled out of the galaxy in a 'galactic hailstorm'

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NASA’s New Horizons Spacecraft Begins First Stages of Pluto Encounter

15 January 2015 - 9:58pm

NASA's New Horizons spacecraft recently began its long-awaited, historic encounter with Pluto. The spacecraft is entering the first of several approach phases that culminate July 14 with the first close-up flyby of the dwarf planet, 4.67 billion miles (7.5 billion kilometers) from Earth.

Huygens: the top 10 discoveries at Titan

15 January 2015 - 3:23pm
Ten years ago, ESA's Huygens probe entered the history books by descending to the surface of Titan, Saturn’s largest moon. Humanity's first successful attempt to land a probe on another world in the outer Solar System took place at 13:34 CET (12:34 GMT) on 14 January 2005.

Galactic zombies roam the cosmos and refuse to die

14 January 2015 - 7:50pm

Cannibalism plays a big part in the life cycle of galaxies, but some rise from the dead as zombies – including one on a collision course with our own

New Exoplanet-hunting Telescopes on Paranal

14 January 2015 - 11:10am
The Next-Generation Transit Survey (NGTS) has achieved first light at ESO’s Paranal Observatory in northern Chile. This project will search for transiting exoplanets — planets that pass in front of their parent star and hence produce a slight dimming of the star’s light that can be detected by sensitive instruments. The telescopes will focus on discovering Neptune-sized and smaller planets, with diameters between two and eight times that of Earth.

Huge circle in Antarctic ice hints at meteorite impact

9 January 2015 - 7:14pm
A 2-kilometre-wide circle of deformed ice discovered in Antarctica may be a site of a large meteorite impact from 2004

‘Bent time’ tips pulsar out of view

9 January 2015 - 5:46pm

One of deep space's spinning "lighthouses" fades from view as it warps space-time, tilting its radio beams away from Earth.

'Planet' Pluto comes into view

9 January 2015 - 3:48pm

The little world is finally about to come into view

Saturn pinpointed to within one mile

9 January 2015 - 11:52am

Astronomers measure Saturn’s position with unprecedented accuracy thanks to a continent-wide radio telescope.

Mercury may be sole survivor of planetary pile-up

8 January 2015 - 6:28pm
Our solar system may have started out with several planets packed closer to the sun than Mercury, much like the planets we see around other stars

Jupiter's eroding core may already be just a husk

8 January 2015 - 1:51pm

The lump of ice and rock at the planet's centre is dissolving like salt in water, and the latest calculations say it's happening twice as fast as we thought

Bright black hole may have blasted early Earth life

8 January 2015 - 12:14pm

The black hole at the centre of our galaxy may have been more active in the past, hurling X-rays at ancient life forms