This image shows a new view of the Milky Way from the Murchison Widefield Array, with the lowest ... [+]
Our Milky Way’s galactic center has long been shrouded in mystery, gas and dust. But cutting-edge radio telescope technology in Western Australia’s radio-quiet Outback has just detected 27 never-before-seen supernova remnants in these galactic nether regions.
Three separate papers all appearing in the journal Publications of the Astronomical Society of Australia detail the findings. The team used new data from the $50 million Murchison Widefield Array (MWA) telescope, to find remnants of 27 massive stars that exploded AS supernovae, reports the International Centre for Radio Astronomy Research (ICRAR) in Perth.
These stars would have been eight or more times more massive than our Sun before their dramatic destruction thousands of years ago, ICRAR reports. And Unlike other instruments, the MWA can find those which are older, further away, or in very empty environments, it notes.
The latest data release from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey, the authors note. And it makes available a further 2,860 square degrees of the GLEAM survey, covering half of the accessible Galactic Plane, across twenty different Megahertz frequency bands.
The new images clearly show what our galaxy would look like if human eyes could see radio waves, says ICRAR.
Natasha Hurley-Walker, an astrophysicist at Curtin University, created the images using the Pawsey Supercomputing Centre in Perth, says ICRAR.
These are the 27 newly-discovered supernova remnants—the remains of stars that ended their lives in ... [+]
“This new view captures low-frequency radio emission from our galaxy, looking both in fine detail and at larger structures,” Hurley-Walker said in a statement. “Our images are looking directly at the middle of the Milky Way.”
The GLEAM survey, says ICRAR, 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 center,” Hurley-Walker said in a statement. “Essentially, different objects have different ‘radio colors,’ so we can use them to work out what kind of physics is at play.”
The team is particularly intrigued by observations of a supernova that lies in an empty region far out of the plane of our galaxy and which is thought to be the very faint remnants of a star that died less than 9,000 years ago, says ICRAR.
If so, the supernova explosion could have been visible to Indigenous people across Australia at that time, Hurley-Walker notes in a statement.
As yet, it’s not known whether this particular event has been described in indigenous historical records. But Duane Hamacher, an expert in cultural astronomy at the University of Melbourne, said in a statement that 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,” Hamacher said in a statement.
What’s next?
The Murchison Widefield Array, the authors note, has been operational since 2013 And is a precursor to the low-frequency component of the Square Kilometre Array (SKA). Once in operation, the SKA will operate in both Australia and South Africa and once completed in 2017 will be the world’s largest radio telescope.
“The MWA is perfect for finding these objects, but it is limited in its sensitivity and resolution,” Hurley-Walker said in a statement. “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.”
