Tag Archives: galaxies

Wide open skies for Australian astronomy

CSIRO’s Australian Square Kilometre Array Pathfinder (ASKAP) telescope is already booked out for much of its first five years of data gathering, even before it formally begins early operations in 2013.

One of CSIRO’s ASKAP antennas at the MRO. Credit: Barry Turner, CSIRO

More than 400 astronomers from over a dozen nations have already signed up to look for pulsars, measure cosmic magnetic fields, and study millions of galaxies.

ASKAP was built at the specifically radio-quiet Murchison Radio-astronomy Observatory (MRO) in Western Australia as a technology demonstrator for the $2 billion Square Kilometre Array radio telescope.
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Massive galaxy survey confirms accelerating Universe

The Universe is definitely getting bigger, faster—and astronomers using the Anglo-Australian Telescope in NSW have confirmed it.

The WiggleZ survey looked at over 200,000 visible galaxies (middle), but also gave insights into dark matter (the green grid that deforms the gravity field) and dark energy (the purple grid). Credit: NASA/JPL-Caltech
The WiggleZ survey looked at over 200,000 visible galaxies (centre), but also gave insights into dark matter (the green grid that deforms the gravity field) and dark energy (the purple grid). Credit: NASA/JPL-Caltec

The results are now in for WiggleZ, a survey of the night sky, spanning 200,000 galaxies and billions of years of cosmic history.

“This puts a nail in it. Clearly the universe is accelerating, and clearly there is something like dark energy,” says Prof Matthew Colless, director of the Australian Astronomical Observatory and a member of the WiggleZ team.
Continue reading Massive galaxy survey confirms accelerating Universe

Telescope of tiles

No moving parts – a new kind of radio telescope
The Murchison Widefield Array is a telescope with no moving parts. Credit: David Herne, ICRAR

Far outback in Western Australia, 32 tiles—flat, stationary sensors—each carrying 16 dipole antennas have begun collecting scientific data.

These first tiles will ultimately form part of a much bigger array of 512 tiles, the Murchison Widefield Array (MWA)—Australia’s second Square Kilometre Array (SKA) demonstrator project. Like CSIRO’s Australian SKA Pathfinder (ASKAP), the MWA is being built at the remote, radio-quiet Murchison Radio-astronomy Observatory (MRO). Continue reading Telescope of tiles

Supercomputers bring theory to life

A DEPICTION OF THE DISTRIBUTION OF MATTER IN AN OBJECT NEARLY TEN MILLION LIGHT YEARS ACROSS AND A THOUSAND TIMES THE MASS OF THE MILKY WAY. THOUSANDS OF THESE EXIST IN THE OBSERVABLE UNIVERSE. CREDIT: GREG POOLE, SWINBURNE UNIVERSITY OF TECHNOLOGY.
A DEPICTION OF THE DISTRIBUTION OF MATTER IN AN OBJECT NEARLY TEN MILLION LIGHT YEARS ACROSS AND A THOUSAND TIMES THE MASS OF THE MILKY WAY. THOUSANDS OF THESE EXIST IN THE OBSERVABLE UNIVERSE. CREDIT: GREG POOLE, SWINBURNE UNIVERSITY OF TECHNOLOGY.

Over aeons of time cosmic gas comes together, stars begin to form, supernovae explode, galaxies collide. And computational astronomers can watch it all unfold inside a supercomputer. That’s the kind of work post-doctoral fellows Rob Crain and Greg Poole are doing at the Swinburne Centre for Astrophysics and Supercomputing. Continue reading Supercomputers bring theory to life

Recording the impact of a super-massive black hole

PARTICLES EMITTING RADIO WAVES STREAM MILLIONS OF LIGHT-YEARS INTO SPACE FROM THE HEART OF THE GALAXY CENTAURUS A. CREDIT: ILANA FEAIN, TIM CORNWELL & RON EKERS (CSIRO). ATCA NORTHERN MIDDLE LOBE POINTING COURTESY R. MORGANTI (ASTRON), PARKES DATA COURTESY N. JUNKES (MPIFR).
PARTICLES EMITTING RADIO WAVES STREAM MILLIONS OF LIGHT-YEARS INTO SPACE FROM THE HEART OF THE GALAXY CENTAURUS A. CREDIT: ILANA FEAIN, TIM CORNWELL & RON EKERS (CSIRO). ATCA NORTHERN MIDDLE LOBE POINTING COURTESY R. MORGANTI (ASTRON), PARKES DATA COURTESY N. JUNKES (MPIFR).

At the centre of a nearby galaxy lurks an object of huge interest, a super-massive black hole. CSIRO scientists have used their radio telescopes to take a picture of the galaxy surrounding it, a task some thought could not be done, because of the sheer size and radio brightness of the scene. The image of Centaurus A took about 1,200 hours of observations and a further 10,000 hours of computer processing to put together, but the work is already beginning to bear fruit.

“We didn’t generate this image just to make a pretty picture,” says lead scientist Ilana Feain of CSIRO Astronomy and Space Science. “We want to understand in detail how the energy from super-massive black holes influences the formation and evolution of their host galaxies.” Continue reading Recording the impact of a super-massive black hole

Galactic archaeology— digging into the Milky Way’s past

ASTRONOMERS ARE HUNTING ‘FOSSIL’ STARS FROM GALAXIES DEVOURED BY THE MILKY WAY CREDIT: HUBBLE HERITAGE TEAM (AURA/STSCI/NASA/ESA)
ASTRONOMERS ARE HUNTING ‘FOSSIL’ STARS FROM GALAXIES DEVOURED BY THE MILKY WAY CREDIT: HUBBLE HERITAGE TEAM (AURA/STSCI/NASA/ESA)

Ken Freeman is hunting for fossils. But he’s not looking for old bones—he’s exploring the very origin and history of our Milky Way galaxy.

Conventional theory says that our galaxy grew big by engulfing smaller ones. If this is correct, stars from the original galaxies should be still identifiable within the main mass of stars via several tell-tale signs, from unusual velocities to spectral types. These stellar fossils would point to the galaxy’s birth and growth. Continue reading Galactic archaeology— digging into the Milky Way’s past

Is the Red Rectangle a cosmic Rosetta Stone?

THE RED RECTANGLE IS A PECULIAR NEBULA WITH SOME STRANGE CHEMICAL PROPERTIES. CREDIT: NASA/ESA/ HANS VAN WINCKEL (CATHOLIC UNIVERSITY OF LEUVEN) /MARTIN COHEN (UCB).
THE RED RECTANGLE IS A PECULIAR NEBULA WITH SOME STRANGE CHEMICAL PROPERTIES. CREDIT: NASA/ESA/ HANS VAN WINCKEL (CATHOLIC UNIVERSITY OF LEUVEN) /MARTIN COHEN (UCB).

Cracking the puzzle of unusual molecules in deep space that absorb some wavelengths of starlight is like unlocking the secrets of the Rosetta Stone, according to Rob Sharp of the Australian National University’s Research School of Astronomy and Astrophysics. “It’s the longest-standing problem in astronomical spectroscopy,” he says.

The identity of the molecules has been a mystery for 80 years, but Rob has now joined forces with chemists at the University of Sydney to try to crack the molecular code. Continue reading Is the Red Rectangle a cosmic Rosetta Stone?

Bringing dark corners of the Universe to light

JOSS BLAND-HAWTHORN HOLDING A PHOTONIC LANTERN, A REVOLUTIONARY DEVICE TO ANALYSE THE LIGHT OF DISTANT STARS, INVENTED IN AUSTRALIA. CREDIT: CHRIS WALSH.
JOSS BLAND-HAWTHORN HOLDING A PHOTONIC LANTERN, A REVOLUTIONARY DEVICE TO ANALYSE THE LIGHT OF DISTANT STARS, INVENTED IN AUSTRALIA. CREDIT: CHRIS WALSH.

Using the Gemini South telescope in Chile, a team of astronomers led by Joss Bland-Hawthorn of the University of Sydney revealed the faint, outer regions of the galaxy called NGC 300, showing that the galaxy is at least twice the size as thought previously. The findings suggest that our own Milky Way galaxy could also be bigger than the textbooks say.

But Joss’s telescope observations are just a part of his contribution to astronomy. He is also helping to pioneer a new technology known as astrophotonics, which uses optical systems to improve our understanding of the Universe. Continue reading Bringing dark corners of the Universe to light

Ten times more galaxies

THE 3.9 METRE ANGLO­-AUSTRALIAN TELESCOPE IS COLLECTING OPTICAL GALAXY DATA FOR THE GAMA SURVEY. CREDIT: BARNABY NORRIS.

A new ‘super survey’ is producing the largest database of galaxy measurements, spanning the last five billion years of cosmic history. The International Galaxy and Mass Assembly (GAMA) project is combining data from ground-and space-based observatories to measure the ‘haloes’ of dark matter that surround galaxies.

“The Cold Dark Matter (CDM) model of cosmology makes predictions about how galaxies cluster and, in many cases, collide and merge,” says Andrew Hopkins, a GAMA team member. “Our measurements of the speeds of galaxies will reveal the distribution of dark matter, and enable us to test the CDM model.”

Continue reading Ten times more galaxies

Spinning galaxies reveal missing matter

PHOTO: DARK MATTER DOMINATES GALAXIES AND GROUPS OF GALAXIES, YET ITS IDENTITY REMAINS UNKNOWN. CREDIT: DAVID MALIN, AUSTRALIAN ASTRONOMICAL OBSERVATORY.
PHOTO: DARK MATTER DOMINATES GALAXIES AND GROUPS OF GALAXIES, YET ITS IDENTITY REMAINS UNKNOWN. CREDIT: DAVID MALIN, AUSTRALIAN ASTRONOMICAL OBSERVATORY.

Australian astronomers have long been contributing to our understanding of a strange cosmological phenomenon—the Universe’s missing matter.

In the early 1970s, Ken Freeman of the Australian National University (ANU) determined that spiral galaxies must contain more matter than we can see. He postulated that dark matter—an invisible material first proposed 40 years earlier—must make up at least half the mass of these galaxies. Now, patches of dark matter are thought to be scattered across the Universe, playing a major role in holding galaxies and groups of galaxies together. Continue reading Spinning galaxies reveal missing matter