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An inland telescope captures the center of the Milky Way, finding the remains of dead stars


An inland telescope captures the center of the Milky Way, finding the remains of dead stars

A new view of the Milky Way from the Murchison Widefield Array, with the lowest frequency in red, the intermediate frequency in green, and the highest frequency in blue. Large gold filaments show a very large magnetic field, supernova remnants are seen as small ball bubbles, and massive star formation regions appear in blue. [The supermassive black hole at the centre of our galaxy is hidden in the bright white region in the centre.] Awards: Dr. Natasha Hurley-Walker (ICRAR / Curtin) and the GLEAM Team

A radio telescope in the interior of Western Australia has captured new spectacular views of the center of the Milky Way galaxy. Images from the Murchison Widefield Array (MWA) telescope show what our galaxy looks like if the human eye can see radio waves.

Astrophysicist Dr. Natasha Hurley-Walker, from the Curtin University node of the International Center for Radio Astronomy Research (ICRAR), created images using the Pawsey Supercomputing Center in Perth. "This new view captures low-frequency radio emissions from our galaxy, seen in fine detail and in larger structures," he said. "Our pictures look directly in the middle of the Milky Way, towards the area that astronomers call the galactic center."

Data for this study came from the MWL GaLactic and Extragalactic All-sky surveys, or GLEAM. The survey has a two minute arc resolution (almost the same as the human eye) and maps the sky using radio waves at frequencies between 72 and 231 MHz (FM radio nearly 100 MHz).

"It's the strength of this wide frequency range that allows us to separate different overlapping objects when we look at the complexity of the galactic center," Dr. Hurley-Walker.

An inland telescope captures the center of the Milky Way, finding the remains of dead stars

27 new supernova remnants discovered – remnants of stars that ended their lives in the explosion of large stars thousands to hundreds of thousands of years ago. Radio images trace the edge of the explosion as they continue their expansion into interstellar space. [Some are huge, larger than the full moon, and others are small and hard to spot in the complexity of the Milky Way.] Awards: Dr. Natasha Hurley-Walker (ICRAR / Curtin) and the GLEAM Team.

"Basically, various objects have different radio colors, so we can use them to find out what kind of physics is being played."

Using these pictures, Dr. Hurley-Walker and his colleagues found the remains of 27 massive stars that exploded in a supernova at the end of their lives. These stars were eight times or larger than our sun before their dramatic destruction thousands of years ago.

Remnants of younger and closer supernovae, or those in very crowded, easily recognizable, and 295 known environments. Unlike other instruments, MWA can find older, more remote, or in very empty environments.

An inland telescope captures the center of the Milky Way, finding the remains of dead stars

Photomosaic 28 of these images capture the Milky Way's arch above the Guilderton Lighthouse in Western Australia, and the Large and Small Magellanic Clouds. The location of a supernova that exploded 9,000 years ago and is visible in the night sky is shown in the figure. Credit: Paean Ng / Extraordinary Imaging

Dr. Hurley-Walker says one of the remains of a newly discovered supernova lies in a region of space that is so empty, far from the plane of our galaxy, and although still very young, is also very dim. "These are the remains of stars that died less than 9,000 years ago, which means that the explosion could be seen by Natives throughout Australia at that time," he said.

An expert in cultural astronomy, Associate Professor Duane Hamacher of the University of Melbourne, said some Aboriginal traditions portray new stars as bright as they appear in the sky, but we don't know of any definitive tradition that describes this particular event. "However, now that we know when and where this supernova appears in the sky, we can work with indigenous elders to see if there are any traditions that describe this cosmic event. If anything, it will be very interesting," he said.

Dr. Hurley-Walker said two of the supernova remnants found were unusual "orphans", found in regions of the sky where there were no massive stars, which means that future searches in other regions might be more successful than astronomers had predicted. Other supernova remnants found in this study are very old, he said. "This is really exciting for us, because it's hard to find the remnants of supernovae in this phase of life – they allow us to look further into the past in the Milky Way."

The MWA Telescope is the forerunner of the world's largest radio telescope, Square Kilometer Array, which will be built in Australia and South Africa starting in 2021. "The MWA is perfect for discovering these objects, but is limited in sensitivity and sensitivity." resolution, "said Dr. Hurley-Walker." The low-frequency portion of the SKA, which will be built in the same location as the MWA, will be thousands of times more sensitive and have a much better resolution, so it must find thousands of supernova remnants formed in the last 100,000 years, even on the other side of the Milky Way. "

Australia's desert telescope looks at the sky in radio colors

Further information:
'Prospective radio supernova remnants detected in the GLEAM survey are more than 345 °… etected_in_GLEAM.pdf

The remaining radio supernova remnants observed by the GLEAM survey above 345 ° … /gleam-survey-ii.pdf

'GaLactic and Extragalactic All-sky Survey' Murchison Widefield Array (GLEAM) II: Galactic Aircraft 345 °… erved_by_GLEAM-1.pdf

Provided by
International Center for Radio Astronomy Research

An inland telescope captures the center of the Milky Way, finds the remains of dead stars (2019, November 20)
taken November 20 2019

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