A radio telescope in the Western Australian outback has captured a spectacular new view of the centre of the galaxy in which we live, the Milky Way.
The image from the Murchison Widefield Array (MWA) telescope shows what our galaxy would look like if human eyes could see radio waves.
This image shows a new view of the Milky Way from the Murchison Widefield Array, with the lowest frequencies in red, middle frequencies in green, and the highest frequencies in blue. Huge golden filaments indicate enormous magnetic fields, supernova remnants are visible as little spherical bubbles, and regions of massive star formation show up in blue. [The supermassive black hole at the centre of our galaxy is hidden in the bright white region in the centre.]
Credit: Dr Natasha Hurley-Walker (ICRAR/Curtin) and the GLEAM Team
Astrophysicist Dr Natasha Hurley-Walker, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR), created the images using the Pawsey Supercomputing Centre in Perth.
"This new view captures low-frequency radio emission from our galaxy, looking both in fine detail and at larger structures," she said.
"Our images are looking directly at the middle of the Milky Way, towards a region astronomers call the Galactic Centre."
The data for the research comes from the GaLactic and Extragalactic All-sky MWA survey, or 'GLEAM' for short.
The survey has a resolution of two arcminutes (about the same as the human eye) and maps the sky using radio waves at frequencies between 72 and 231 MHz (FM radio is near 100 MHz).
"It's the power of this wide frequency range that makes it possible for us to disentangle different overlapping objects as we look toward the complexity of the Galactic Centre," Dr Hurley-Walker said.
"Essentially, different objects have different 'radio colours', so we can use them to work out what kind of physics is at play."
Using the images, Dr Hurley-Walker and her colleagues discovered the remnants of 27 massive stars that exploded in supernovae at the end of their lives.
These stars would have been eight or more times more massive than our Sun before their dramatic destruction thousands of years ago.
Younger and closer supernova remnants, or those in very dense environments, are easy to spot, and 295 are already known.
Unlike other instruments, the MWA can find those which are older, further away, or in very empty environments.
Dr Hurley-Walker said one of the newly-discovered supernova remnants lies in such an empty region of space, far out of the plane of our galaxy, and so despite being quite young, is also very faint.
"It's the remains of a star that died less than 9,000 years ago, meaning the explosion could have been visible to Indigenous people across Australia at that time," she said.
An expert in cultural astronomy, Associate Professor Duane Hamacher from the University of Melbourne, said some Aboriginal traditions do describe bright new stars appearing in the sky, but we don't know of any definitive traditions that describe this particular event.
"However, now that we know when and where this supernova appeared in the sky, we can collaborate with Indigenous elders to see if any of their traditions describe this cosmic event. If any exist, it would be extremely exciting," he said.
Dr Hurley-Walker said two of the supernova remnants discovered are quite unusual "orphans", found in a region of sky where there are no massive stars, which means future searches across other such regions might be more successful than astronomers expected.
Other supernova remnants discovered in the research are very old, she said.
"This is really exciting for us, because it's hard to find supernova remnants in this phase of life--they allow us to look further back in time in the Milky Way."
The MWA telescope is a precursor to the world's largest radio telescope, the Square Kilometre Array, which is due to be built in Australia and South Africa from 2021.
"The MWA is perfect for finding these objects, but it is limited in its sensitivity and resolution," Dr Hurley-Walker said.
"The low-frequency part of the SKA, which will be built at the same site as the MWA, will be thousands of times more sensitive and have much better resolution, so should find the thousands of supernova remnants that formed in the last 100,000 years, even on the other side of the Milky Way."
The new images of the Galactic Centre can be viewed on the GLEAMoscope or the GLEAM app.
Publications: 'New candidate radio supernova remnants detected in the GLEAM survey over 345° < l < 60°, 180° < l < 240°', published in Publications of the Astronomical Society of Australia (PASA) on November 20th, 2019.
'Candidate radio supernova remnants observed by the GLEAM survey over 345° < l < 60°, 180° < l < 240°', published in Publications of the Astronomical Society of Australia (PASA) on November 20th, 2019.
'GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey II: Galactic Plane 345° < l < 67°, 180° < l < 240°', published in Publications of the Astronomical Society of Australia (PASA) on November 20th, 2019.
High-resolution images, an animation and a simulation are available from http://www.
Dr Natasha Hurley-Walker (ICRAR / Curtin University)
Ph: +61 8 9266 9178 E: Natasha.Hurley-Walker@curtin.edu.au
Pete Wheeler (Media Contact, ICRAR)
Ph: +61 423 982 018 E: Pete.Wheeler@icrar.org
Lucien Wilkinson (Media Contact, Curtin University)
Ph: +61 401 103 683 E: Lucien.Wilkinson@curtin.edu.au
Pete Wheeler | EurekAlert!
Weizmann physicists image electrons flowing like water
12.12.2019 | Weizmann Institute of Science
Revealing the physics of the Sun with Parker Solar Probe
12.12.2019 | NASA/Goddard Space Flight Center
More than one hundred and fifty years have passed since the publication of James Clerk Maxwell's "A Dynamical Theory of the Electromagnetic Field" (1865). What would our lives be without this publication?
It is difficult to imagine, as this treatise revolutionized our fundamental understanding of electric fields, magnetic fields, and light. The twenty original...
In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.
Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...
The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.
Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...
Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.
Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...
Using a clever technique that causes unruly crystals of iron selenide to snap into alignment, Rice University physicists have drawn a detailed map that reveals...
03.12.2019 | Event News
15.11.2019 | Event News
15.11.2019 | Event News
12.12.2019 | Physics and Astronomy
12.12.2019 | Physics and Astronomy
12.12.2019 | Life Sciences